Requesting Feedback Information in Multi-Downlink Scheduling

ABSTRACT

A wireless device receives a downlink control information that indicates: physical downlink shared channels (PDSCHs) across slots in a cell; group indexes of the PDSCHs, respectively, with each of the group indexes being one of a first value or a second value; and an uplink control channel for transmitting feedback information of one or more PDSCHs with one or more respective group indexes being a same value as a first group index of a first PDSCH of the PDSCHs. The wireless devices determines that the first group index of the first PDSCH is the first value. The wireless device transmits, via the uplink control channel, feedback information of one or more first PDSCHs, from the PDSCHs, with one or more respective first group indexes being the first value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/170,722, filed Apr. 5, 2021, which is hereby incorporated byreference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17 shows an example of HARQ feedback timing determination,according to some embodiments.

FIG. 18 shows an example of grouping PDSCHs using scheduling DCIs,according to some embodiments.

FIG. 19 shows an example of grouping PDSCHs using scheduling DCIs,according to some embodiments.

FIG. 20 shows an example of HARQ-ACK transmission associated with a DCIscheduling multiple PDSCHs, according to some embodiments.

FIG. 21A and FIG. 21B show an example of requesting HARQ feedback of oneor more PDSCH groups, according to some embodiments.

FIG. 22 shows an example of grouping PDSCHs scheduled by a DCI,according to some embodiments.

FIG. 23A and FIG. 23B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments.

FIG. 24A and FIG. 24B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments.

FIG. 25A and FIG. 25B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments.

FIG. 26A and FIG. 26B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments.

FIG. 27 shows an example of requesting HARQ feedback of PDSCH groups bya DCI scheduling multiple PDSCHs and two respective PUCCHs, according tosome embodiments.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B ={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses. For the sake of brevity andlegibility, the present disclosure does not explicitly recite each andevery permutation that may be obtained by choosing from the set ofoptional features. The present disclosure is to be interpreted asexplicitly disclosing all such permutations. For example, a systemdescribed as having three optional features may be embodied in sevenways, namely with just one of the three possible features, with any twoof the three possible features or with three of the three possiblefeatures.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (e.g.hardware with a biological element) or a combination thereof, which maybe behaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language configured to beexecuted by a hardware machine (such as C, C++, Fortran, Java, Basic,Matlab or the like) or a modeling/simulation program such as Simulink,Stateflow, GNU Octave, or Lab VIEWMathScript. It may be possible toimplement modules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The mentioned technologies areoften used in combination to achieve the result of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interface to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interface is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (IoT) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-CN node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNBs 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNBs 162 may include three sets of antennasto respectively control three cells (or sectors). Together, the cells ofthe gNBs 160 and the ng-eNBs 162 may provide radio coverage to the UEs156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNBs 162 may beconnected to the 5G-CN 152 by means of an NG interface and to other basestations by an Xn interface. The NG and Xn interfaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNBs 160 and/or the ng-eNBs 162 may be connectedto the UEs 156 by means of a Uu interface. For example, as illustratedin FIG. 1B, gNB 160A may be connected to the UE 156A by means of a Uuinterface. The NG, Xn, and Uu interfaces are associated with a protocolstack. The protocol stacks associated with the interfaces may be used bythe network elements in FIG. 1B to exchange data and signaling messagesand may include two planes: a user plane and a control plane. The userplane may handle data of interest to a user. The control plane mayhandle signaling messages of interest to the network elements.

The gNBs 160 and/or the ng-eNBs 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interfaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interface. The NG-U interface may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide, for example, NGinterface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interface. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interface associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interface associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interface that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterface between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2, or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3, the SDAPs 215 and 225 may perform QoS flow handling.The UE 210 may receive services through a PDU session, which may be alogical connection between the UE 210 and a DN. The PDU session may haveone or more QoS flows. A UPF of a CN (e.g., the UPF 158B) may map IPpackets to the one or more QoS flows of the PDU session based on QoSrequirements (e.g., in terms of delay, data rate, and/or error rate).The SDAPs 215 and 225 may perform mapping/de-mapping between the one ormore QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterface, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interface, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3, PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request (ARQ), and removal of duplicate data unitsreceived from MACs 212 and 222, respectively. The RLCs 213 and 223 maysupport three transmission modes: transparent mode (TM); unacknowledgedmode (UM); and acknowledged mode (AM). Based on the transmission mode anRLC is operating, the RLC may perform one or more of the notedfunctions. The RLC configuration may be per logical channel with nodependency on numerologies and/or Transmission Time Interval (TTI)durations. As shown in FIG. 3, the RLCs 213 and 223 may provide RLCchannels as a service to PDCPs 214 and 224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TB s) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3, the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3, the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG. 3), add corresponding headers,and forward their respective outputs to the next lower layer. Forexample, the PDCP 224 may perform IP-header compression and cipheringand forward its output to the RLC 223. The RLC 223 may optionallyperform segmentation (e.g., as shown for IP packet m in FIG. 4A) andforward its output to the MAC 222. The MAC 222 may multiplex a number ofRLC PDUs and may attach a MAC subheader to an RLC PDU to form atransport block. In NR, the MAC subheaders may be distributed across theMAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders may beentirely located at the beginning of the MAC PDU. The NR MAC PDUstructure may reduce processing time and associated latency because theMAC PDU subheaders may be computed before the full MAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an SDU length field for indicating thelength (e.g., in bytes) of the MAC SDU to which the MAC subheadercorresponds; a logical channel identifier (LCID) field for identifyingthe logical channel from which the MAC SDU originated to aid in thedemultiplexing process; a flag (F) for indicating the size of the SDUlength field; and a reserved bit (R) field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6, a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG.1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAIs associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAIs associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAIs, or a list of TAIs. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 μs. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30kHz/2.3μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8. An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8. An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink BWP from a set of configured uplinkBWPs if a downlink BWP index of the downlink BWP and an uplink BWP indexof the uplink BWP are the same. For unpaired spectra, a UE may expectthat a center frequency for a downlink BWP is the same as a centerfrequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a BWP inactivity timer at anyappropriate time. For example, the UE may start or restart the BWPinactivity timer (a) when the UE detects a DCI indicating an activedownlink BWP other than a default downlink BWP for a paired spectraoperation; or (b) when a UE detects a DCI indicating an active downlinkBWP or active uplink BWP other than a default downlink BWP or uplink BWPfor an unpaired spectra operation. If the UE does not detect DCI duringan interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWPinactivity timer toward expiration (for example, increment from zero tothe BWP inactivity timer value, or decrement from the BWP inactivitytimer value to zero). When the BWP inactivity timer expires, the UE mayswitch from the active downlink BWP to the default downlink BWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9, the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9, the UE may switch from the BWP 902 to the BWP 904 at a switchingpoint 908. The switching at the switching point 908 may occur for anysuitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPCell 1011, an SCell 1012, and an SCell 1013. The PUCCH group 1050includes three downlink CCs in the present example: a PCell 1051, anSCell 1052, and an SCell 1053. One or more uplink CCs may be configuredas a PCell 1021, an SCell 1022, and an SCell 1023. One or more otheruplink CCs may be configured as a primary Scell (PSCell) 1061, an SCell1062, and an SCell 1063. Uplink control information (UCI) related to thedownlink CCs of the PUCCH group 1010, shown as UCI 1031, UCI 1032, andUCI 1033, may be transmitted in the uplink of the PCell 1021. Uplinkcontrol information (UCI) related to the downlink CCs of the PUCCH group1050, shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted inthe uplink of the PSCell 1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the PCell 1021 and the PSCell 1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS) / physical broadcast channel (PBCH) blockthat includes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 ms). A burst may berestricted to a half-frame (e.g., a first half-frame having a durationof 5 ms). It will be understood that FIG. 11A is an example, and thatthese parameters (number of SS/PBCH blocks per burst, periodicity ofbursts, position of burst within the frame) may be configured based on,for example: a carrier frequency of a cell in which the SS/PBCH block istransmitted; a numerology or subcarrier spacing of the cell; aconfiguration by the network (e.g., using RRC signaling); or any othersuitable factor. In an example, the UE may assume a subcarrier spacingfor the SS/PBCH block based on the carrier frequency being monitored,unless the radio network configured the UE to assume a differentsubcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB 1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB 1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g. a maximum number) of front-loadedDMRS symbols for PDSCH. A DMRS configuration may support one or moreDMRS ports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation. Whether a downlink PT-RS is present or not maydepend on an RRC configuration. The presence and/or pattern of thedownlink PT-RS may be configured on a UE-specific basis using acombination of RRC signaling and/or an association with one or moreparameters employed for other purposes (e.g., modulation and codingscheme (MCS)), which may be indicated by DCI. When configured, a dynamicpresence of a downlink PT-RS may be associated with one or more DCIparameters comprising at least MCS. An NR network may support aplurality of PT-RS densities defined in the time and/or frequencydomains. When present, a frequency domain density may be associated withat least one configuration of a scheduled bandwidth. The UE may assume asame precoding for a DMRS port and a PT-RS port. A number of PT-RS portsmay be fewer than a number of DMRS ports in a scheduled resource.Downlink PT-RS may be confined in the scheduled time/frequency durationfor the UE. Downlink PT-RS may be transmitted on symbols to facilitatephase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g. maximum number) of front-loadedDMRS symbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, uplink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRS sequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RS subframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure P1 may enable a UE measurement ontransmit (Tx) beams of a transmission reception point (TRP) (or multipleTRPs), e.g., to support a selection of one or more base station Tx beamsand/or UE Rx beams (shown as ovals in the top row and bottom row,respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweepfor a set of beams (shown, in the top rows of P1 and P2, as ovalsrotated in a counter-clockwise direction indicated by the dashed arrow).Beamforming at a UE may comprise an Rx beam sweep for a set of beams(shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwisedirection indicated by the dashed arrow). Procedure P2 may be used toenable a UE measurement on Tx beams of a TRP (shown, in the top row ofP2, as ovals rotated in a counter-clockwise direction indicated by thedashed arrow). The UE and/or the base station may perform procedure P2using a smaller set of beams than is used in procedure P1, or usingnarrower beams than the beams used in procedure P1. This may be referredto as beam refinement. The UE may perform procedure P3 for Rx beamdetermination by using the same Tx beam at the base station and sweepingan Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-ConfigIndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSl-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aTypel-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:

RA-RNTI=1+s_id+14×t_id+80×f_id+14×80×8×ul_carrier_id

where s_id may be an index of a first OFDM symbol of the PRACH occasion(e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACHoccasion in a system frame (e.g.,0≤t_id<80), f_id may be an index of thePRACH occasion in the frequency domain (e.g., 0≤f_id<8), andul_carrier_id may be a UL carrier used for a preamble transmission(e.g., 0 for an NUL carrier, and 1 for an SUL carrier).

The UE may transmit the Msg 3 1313 in response to a successful receptionof the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312).The Msg 3 1313 may be used for contention resolution in, for example,the contention-based random access procedure illustrated in FIG. 13A. Insome scenarios, a plurality of UEs may transmit a same preamble to abase station and the base station may provide an RAR that corresponds toa UE. Collisions may occur if the plurality of UEs interpret the RAR ascorresponding to themselves. Contention resolution (e.g., using the Msg3 1313 and the Msg 4 1314) may be used to increase the likelihood thatthe UE does not incorrectly use an identity of another the UE. Toperform contention resolution, the UE may include a device identifier inthe Msg 3 1313 (e.g., a C-RNTI if assigned, a TC RNTI included in theMsg 2 1312, and/or any other suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-Preamblelndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceld). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgment for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1331 may be transmitted in an uplink transmission by the UE. Msg A1331 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1332 after or in response to transmittingthe Msg A 1331. The Msg B 1332 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1332.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more DCI formats. For example, DCI format0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may bea fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1may be used for scheduling of PUSCH in a cell (e.g., with more DCIpayloads than DCI format 0_0 ). DCI format 1_0 may be used forscheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCIformat (e.g., with compact DCI payloads). DCI format 1_1 may be used forscheduling of PDSCH in a cell (e.g., with more DCI payloads than DCIformat 1_0 ). DCI format 2_0 may be used for providing a slot formatindication to a group of UEs. DCI format 2_1 may be used for notifying agroup of UEs of a physical resource block and/or OFDM symbol where theUE may assume no transmission is intended to the UE. DCI format 2_2 maybe used for transmission of a transmit power control (TPC) command forPUCCH or PUSCH. DCI format 2_3 may be used for transmission of a groupof TPC commands for SRS transmissions by one or more UEs. DCI format(s)for new functions may be defined in future releases. DCI formats mayhave different DCI sizes, or may share the same DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a CORESET in thetime-frequency domain. In the example of FIG. 14A, a first CORESET 1401and a second CORESET 1402 occur at the first symbol in a slot. The firstCORESET 1401 overlaps with the second CORESET 1402 in the frequencydomain. A third CORESET 1403 occurs at a third symbol in the slot. Afourth CORESET 1404 occurs at the seventh symbol in the slot. CORESETsmay have a different number of resource blocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgments forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgments after receiving a DL-SCH transport block. Uplink controlsignaling may comprise channel state information (CSI) indicatingchannel quality of a physical downlink channel. The UE may transmit theCSI to the base station. The base station, based on the received CSI,may determine transmission format parameters (e.g., comprisingmulti-antenna and beamforming schemes) for a downlink transmission.Uplink control signaling may comprise scheduling requests (SR). The UEmay transmit an SR indicating that uplink data is available fortransmission to the base station. The UE may transmit a UCI (e.g., HARQacknowledgments (HARQ-ACK), CSI report, SR, and the like) via a physicaluplink control channel (PUCCH) or a physical uplink shared channel(PUSCH). The UE may transmit the uplink control signaling via a PUCCHusing one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a PUCCH resource from the PUCCHresource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE maydetermine the PUCCH resource based on a PUCCH resource indicator in aDCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. Athree-bit PUCCH resource indicator in the DCI may indicate one of eightPUCCH resources in the PUCCH resource set. Based on the PUCCH resourceindicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using aPUCCH resource indicated by the PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15, but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15.

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3, and FIG. 4A. For transmit processing, the PHY layer mayperform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3, and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15, a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15, the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g. RRC messages) comprising configuration parameters of a pluralityof cells (e.g. primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g. two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g. as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g. the timer may be started or restarted from a value or may bestarted from zero and expire once it reaches the value). The duration ofa timer may not be updated until the timer is stopped or expires (e.g.,due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

The hybrid-ARQ (hybrid automatic repeat request, HARQ) mechanism in theMAC layer targets very fast transmissions. A wireless device may providefeedback on success (e.g., an ACK) or failure (e.g., a NACK) of adownlink transmission (e.g., a PDSCH) to a base station for eachscheduled/candidate transport block. A HARQ-ACK information bit value of0 represents a negative acknowledgment (NACK) while a HARQ-ACKinformation bit value of 1 represents a positive acknowledgment (ACK).

It may be possible to attain a very low error rate probability of theHARQ feedback, which may come at a cost in transmission resources suchas power. For example, a feedback error rate of 0.1-1% may bereasonable, which may result in a HARQ residual error rate of a similarorder. This residual error rate may be sufficiently low in many cases.In some services requiring ultra-reliable delivery of data with lowlatency, e.g., URLLC, this residual error rate may not be tolerable. Insuch cases, the feedback error rate may be decreased and an increasedcost in feedback signaling may be accepted, and/or additionalretransmissions may be performed without relying on feedback signaling,which comes at a decreased spectral efficiency.

HARQ protocol may be a primary way of handling retransmissions in awireless technology, e.g., NR. In case of an erroneously receivedpacket, a retransmission may be required. Despite it not being possibleto decode the packet, a received signal may still contain information,which may be lost by discarding the erroneously received packet. HARQprotocol with soft combining may address this shortcoming. In HARQ withsoft combining, the wireless device may store the erroneously receivedpacket in a buffer memory, and later combine the received packet withone or more retransmissions to obtain a single, combinedpacket/transport block that may be more reliable than its constituents.Decoding of the error-correction code operates on the combined signal.Retransmissions of codeblock groups that form a transport block may behandled by the physical layer and/or MAC layer.

The HARQ mechanism typically comprises multiple stop-and-wait protocols,each operating on a single transport block. In a stop-and-wait protocol,a transmitter stops and waits for an acknowledgment after eachtransmitted transport block. This protocol requires a single bitindicating positive or negative acknowledgment of the transport block;however, the throughput is low due to waiting after each transmission.Multiple stop-and-wait processes may operate in parallel, e.g., whilewaiting for acknowledgment from one HARQ process, the transmitter maytransmit data of another HARQ process. The multiple parallel HARQprocesses may form a HARQ entity, allowing continuous transmission ofdata. A wireless device may have one HARQ entity per carrier. A HARQentity may support spatial multiplexing of more than four layers to asingle device in the downlink, where two transport blocks may betransmitted in parallel on the same transport channel. The HARQ entitymay have two sets of HARQ processes with independent HARQacknowledgments.

A wireless technology may use an asynchronous HARQ protocol in thedownlink and/or uplink, e.g., the HARQ process which the downlink and/oruplink transmission relates to, may be explicitly and/or implicitlysignaled. For example, the downlink control information (DCI) schedulinga downlink transmission may signal the corresponding HARQ process.Asynchronous HARQ operation may allow dynamic TDD operation, and may bemore efficient when operating in unlicensed spectra, where it may not bepossible to guarantee that scheduled radio resources are available atthe time for synchronous retransmissions.

Large transport block sizes may be segmented into multiple codeblocksprior to coding, each with its own CRC, in addition to an overall TBCRC. Errors may be detected on individual codeblocks based on their CRC,as well as on the overall TB. The base station may configure thewireless device with retransmissions based on groups of codeblocks,e.g., codeblock groups (CBGs). If per-CBG retransmission is configured,feedback is provided pre CBG. A TB may comprise of one or more CBGs. ACBG that a codeblock belongs to may be determined based on an initialtransmission and may be fixed.

In the downlink, retransmissions may be scheduled in a same way as newdata. For example, retransmissions may be scheduled at any time and anyfrequency location within a downlink cell and/or an active downlink BWPof a cell. A downlink scheduling assignment may contain necessaryHARQ-related control signaling, e.g., HARQ process number; new-dataindicator (NDI); CBG transmit indicator (CBGTI) and CBG flush indicator(CBGFI) in case per-CBG retransmission is configured; and/or informationto schedule the transmission of the acknowledgment (ACK/NACK) in anuplink (e.g., a PUCCH), such as timing and resource indicationinformation.

Upon receiving a downlink scheduling assignment in the DCI, the wirelessdevice tries to decode the TB, e.g., after soft combining with previousattempts/receptions of the TB. Transmissions and retransmissions may bescheduled in a same framework. The wireless device may determine whetherthe transmission is a new transmission or a retransmission based on theNDI field in the DCI. An explicit NDI may be included for the scheduledTB as part of the scheduling information in the downlink. The NDI fieldmay comprise one or more NDI bits per TB (and/or CBG). An NDI bit may betoggled for a new transmission, and not toggled for a retransmission. Incase of a new transmission, the wireless device flushes soft buffercorresponding to the new transmission before receiving/storing the newtransmission. In case of a retransmission, the wireless device mayperform a soft combining of the received data with stored data in thesoft buffer for the corresponding HARQ process based on the downlinkscheduling assignment.

A time gap/interval/offset (e.g., K1) from a downlink datareception/resource to a transmission of a HARQ ACK/NACK corresponding tothe downlink data may be fixed, e.g., multiple subframes/slots/symbols(e.g., three ms, 4 slots). This scheme with pre-defined timing instantsfor ACK/NACK may not blend well with dynamic TDD and/or unlicensedoperation. A more flexible scheme, capable of dynamically controllingthe ACK/NACK transmission timing may be adopted. For example, a DLscheduling DCI may comprise a PDSCH-to-HARQ_feedback timing field tocontrol/indicate the transmission timing of an ACK/NACK corresponding toa data scheduled by the DL scheduling DCI in an uplink transmission(e.g., PUCCH). The PDSCH-to-HARQ_feedback timing field in the DCI may beused as an index of one or more indexes of K1 values in a pre-definedand/or RRC-configured table (e.g., a HARQ timing table). The K1 valuemay provide information of a gap/interval/offset between a second timeto transmit the HARQ ACK/NACK relative to a first time of the receptionof data (e.g., physical DL shared channel (PDSCH)).

FIG. 17 shows an example of HARQ feedback timing determination,according to some embodiments. In this example, three DCIs are receivedin slots S0, S1, and S3 that schedule three downlink assignments in thesame slots. In each downlink assignment, different HARQ feedback timingindices are indicated, e.g., in S0: 3, in S1: 2, and in S3: 0. Theindicated indices (PDSCH-to-HARQ_feedback timing field) point to theHARQ timing table, e.g., for S0: T3 in indicated that points to S4 fortransmission of the uplink ACK/NACK, for S1: T2 in indicated that pointsto S4 for transmission of the uplink ACK/NACK, for S3: T0 in indicatedthat points to S4 for transmission of the uplink ACK/NACK. As a result,all three downlink assignments are acknowledged in the same slot, S4.The wireless device multiplexes the three acknowledgments and transmitsthe three acknowledgments in slot S4.

A wireless devices may support a baseline processing time/capability.Some wireless devices may support additional aggressive/fasterprocessing time/capability. A wireless device may report to a basestation a processing capability, e.g. per sub-carrier spacing.

A wireless device may determine a resource for HARQ ACK/NACKtransmission, e.g. frequency resource and/or PUCCH format and/or codedomain, based on a location of a PDCCH (e.g., a starting control channelelement (CCE) index) scheduling the transmission. The schedulingPDCCH/DCI may comprise a field, e.g., PUCCH resource indicator (PRI)field, that indicates a frequency resource for an uplink transmission ofthe HARQ ACK/NACK transmission. For example, the PRI field may be anindex selecting one of a plurality of pre-defined and/or RRC-configuredPUCCH resource sets.

A wireless device may multiplex a plurality of HARQ feedback bits thatare scheduled for transmission in the uplink at a same time/slot, forexample, in a carrier aggregation scenario and/or when per-CBGretransmission is configured. The wireless device may multiplex multipleACK/NACK bits of multiple TBs and/or CBGs into one multi-bit HARQfeedback message/codebook. The multiple ACK/NACK bits may be multiplexedbased on a semi-static codebook and/or a dynamic codebook. A basestation, via RRC configuration, may configure either the semi-staticcodebook or the dynamic codebook for a cell configured with PUCCHresources (e.g., a primary cell, a PUCCH cell)

The semi-static codebook may be viewed as a matrix consisting of a timedomain dimension and a component-carrier (and/or CBG and/or MIMO layer)dimension, both of which may be semi-statically configured and/orpre-defined. A size of the time domain dimension may be given by amaximum and/or a minimum HARQ ACK/NACK timing indicated in thepre-defined and/or RRC-configured table of HARQ ACK/NACK timings. A sizeof the component-carrier domain may be given by a number of simultaneousTBs and/or CBGs across all component carriers. A codebook size may bedetermined based on the time domain dimension and the component-carrierdimension for a semi-static codebook, regardless of actual scheduledtransport blocks/PDSCHs. A number of bits to transmit in a HARQfeedback/report is determined based on one or more RRC configurationparameters. An appropriate format (e.g., PUCCH format) for uplinkcontrol signaling may be selected based on a codebook size (e.g., anumber of HARQ ACK/NACK bits). Each entry of the matrix may represent adecoding outcome, e.g. positive (ACK) or negative (NACK)acknowledgments, of the corresponding transmission. One or more of theentries of the codebook matrix may not correspond to a downlinktransmission opportunity (e.g., a PDSCH occasion), for which a NACK isreported. This may increase a codebook robustness, e.g., in case ofmissed downlink assignments, and the base station may schedule aretransmission of the missed TB/CBG. The size of the semi-staticcodebook may be very large.

The dynamic codebook may be used to address the issue with thepotentially large size of the semi-static codebook. With the dynamiccodebook, only the ACK/NACK information of scheduled assignments,including one or more semi-persistent scheduling, may be included in thereport, e.g., not all carriers as in semi-static codebook. A size of thedynamic codebook may be dynamically varying, e.g., as a function of anumber of scheduled carriers and/or as a function of a number ofscheduled transport blocks. To maintain a same understanding of thedynamic codebook size, which is prone to error in the downlink controlsignaling, a downlink assignment index (DAI) may be included in thescheduling DCI. The DAI field may comprise a counter DAI (cDAI) and atotal DAI (tDAI), e.g., in case of carrier aggregation. The counter DAIin the scheduling DCI indicates a number of scheduled downlinktransmissions (PDSCH reception(s)/SPS PDSCH release(s)) up to the pointthe DCI was received, in a carrier first, PDCCH monitoring occasionindex second manner. The total DAI in the scheduling DCI indicates atotal number of scheduled downlink transmissions across all carriers upto the point the DCI was received. A highest cDAI at a current time isequal to the tDAI at this time.

The base station (BS) may configure a UE with enhanced dynamic codebookfor HARQ feedback operation. The BS may trigger a group of DLtransmissions, e.g. PDSCHs, for example, in an enhanced dynamic codebookoperation. For example, one or more fields in a DCI may indicate one ormore PDSCHs/PDCCHs to be acknowledged via an indicated UL resource. Forexample, the group of DL transmissions may comprise one or more HARQprocesses, and/or may overlap with one or more slots/subframes, and/ormay derived from a dynamic time window. The DCI may be carrying a DLscheduling assignment and/or an UL grant and/or a DCI may not becarrying a scheduling grant. The DCI may comprise one or more HARQfeedback timing values indicating the UL resource.

A DCI scheduling a DL assignment, e.g. PDSCH, may associate the PDSCH toa group. For example, the DCI may comprise a field indicating a groupindex. For example, a PDSCH scheduled by a first DCI format (e.g. DCIformat 1_0) may be associated with a pre-defined group (e.g. PDSCHgroup#0). For example, an SPS PDSCH occasion may be associated with apre-defined group. For example, and SPS PDSCH occasion may be associatedwith a first group, wherein the activation DCI indicates an index of thefirst group. For example, an SPS release PDCCH may be associated with apre-defined group. For example, the SPS release PDCCH may indicate anindex of a group.

The base station may schedule a first PDSCH with aPDSCH-to-HARQ-feedback timing, e.g. K1 value, in a channel occupancytime (COT) with a first group index. The PDSCH-to-HARQ-feedback timingmay have a non-numerical/inapplicable value. The BS may schedule one ormore PDSCHs after the first PDSCH in the same COT, and may assign thefirst group index to the one or more PDSCHs. At least one of the one ormore PDSCHs may be scheduled with a numerical K1 value.

The DCI may indicate a new ACK-feedback group indicator (NFI) for eachPDSCH group. The NFI may operate as a toggle bit. For example, the UEmay receive a DCI that indicates the NFI is toggled for a PDSCH group.The UE may discard one or more HARQ feedbacks for one or more PDSCHs inthe PDSCH group. The one or more PDSCHs may be associated/scheduled withone or more non-numerical K1 values and/or numerical K1 values. The UEmay expect DAI values of the PDSCH group to be reset.

A DCI (e.g., non-fallback DCI) scheduling a PDSCH may indicate a NFI forthe scheduled group (e.g., based on the group index of the scheduledPDSCH). For example, T-DAI may be indicated in a (non-fallback) DCIscheduling PDSCH for the scheduled group if more than one DL cell isconfigured. For example, RRC message(s) may configure/indicate that theDCI may indicate NFI and/or T-DAI for a non-scheduled PDSCH group, e.g.,with single or multiple configured DL cells.

A number of HARQ-ACK bits for one PDSCH group may change betweensuccessive requests for HARQ-ACK feedback for the same PDSCH group,e.g., in response to a NFI toggling (indicating a reset of the PDSCHgrouping). HARQ-ACK feedback for (all) PDSCHs in a same PDSCH group maybe carried/reported in a same PUCCH/PUSCH transmission. DAI (c-DAIand/or T-DAI) values may be accumulated within a PDSCH group. Forexample, DAI values (C-DAI and/or T-DAI) may be accumulated within aPDSCH group until NFI for the PDSCH group is toggled. The C-DAI andT-DAI for a PDSCH group may be reset when the NFI for the PDSCH group istoggled. C-DAI and T-DAI may not be reset by PUCCH transmissionoccasions. A UE may signal, e.g., as part of UE capability signaling,whether it supports the PDSCH grouping feature (enhanced dynamiccodebook) or not.

The UE may be configured with enhanced dynamic codebook. The UE receivea first DCI format (e.g. DCI format 1_0) scheduling one or more PDSCHs.The one or more PDSCHs may be associated with a PDSCH group (e.g. apre-defined PDSCH group, e.g. group#0). The first DCI format may notindicate an NFI value for the PDSCH group. The UE may determine the NFIvalue based on a second DCI format (e.g. DCI format 1_1) indicating theNFI value for the PDSCH group. The UE may detect the second DCI formatsince a last scheduled PUCCH and before a PUCCH occasion, wherein thesecond PUCCH occasion may comprise HARQ feedback corresponding to aPDSCH scheduled with the first DCI format. The last scheduled PUCCH maycomprise HARQ feedback for the PDSCH group. The UE may not detect thesecond DCI that indicates the NFI value for the PDSCH group, and the UEmay assume that the one or more PDSCHs scheduled by the first DCI formatdo not belong to any PDSCH group, and the UE may report the HARQfeedback of at least one PDSCH scheduled by the first DCI format since alast/latest PUCCH occasion.

A DCI may request/trigger HARQ feedback for one or more groups ofPDSCHs, e.g. via a same PUCCH/PUSCH resource. HARQ feedbacks formultiple DL transmissions, e.g. PDSCHs, in a same group, may betransmitted/multiplexed in a same PUCCH/PUSCH resource. Counter DAI andtotal DAI values may be incremented/accumulated within a PDSCH group. Inan example, the DCI may request/trigger HARQ feedback for more than onePDSCH group via a PUCCH.

The wireless device may generate a first sub-codebook comprising firstHARQ-ACK information associated with a first PDSCH group index. Thewireless device may generate the first HARQ-ACK information for a PUCCHtransmission occasion in a slot. The first HARQ-ACK information maycorrespond (only) to detections of DCI formats each providing a samevalue of (scheduled) PDSCH group index (e.g., g) and/or NFI associatedwith the scheduled PDSCH group index (e.g., h(g)). The first HARQ-ACKinformation may correspond to detections of second DCI formats that donot provide a value of (scheduled) PDSCH group index (g) and/or NFI(h(g)). The second DCI formats may be associated with a same value of(scheduled) PDSCH group index (g) and/or NFI (h(g)). At least one of theDCI formats (first and second DCI formats) may provide a value of HARQfeedback timing indicator (k) that indicates the slot. At least one ofthe DCI formats may provide a value for NFI (h(g)).

The wireless device may generate a second sub-codebook comprising secondHARQ-ACK information associated with a second PDSCH group index. Thewireless device may generate the first HARQ-ACK information for a PUCCHtransmission occasion in a slot. The second HARQ-ACK information maycorrespond to detections of DCI formats each providing a same value of(non-scheduled) PDSCH group index (e.g., (g+1)mod2) and/or NFIassociated with the PDSCH group index (e.g., h((g+1)mod2). The secondHARQ-ACK information may correspond to detections of second DCI formatsthat do not provide a value of PDSCH group index and/or NFI. The secondDCI formats may be associated with a same value of PDSCH group indexand/or NFI. At least one of the DCI formats may provide a value for NFI.The PUCCH transmission occasion may be a last one for multiplexing thesecond HARQ-ACK information and/or may not be after a PUCCH transmissionoccasion of the other PDSCH group.

In an example, if a value of a number of requested PDSCH group(s) field(e.g., q) in the (last) DCI format providing the value of PDSCH groupindex (g) is a first value (e.g., q=0), the UE may include (only) thefirst HARQ-ACK information for multiplexing in the PUCCH transmissionoccasion. In an example, if the value of the number of requested PDSCHgroup(s) field (e.g., q) in the (last) DCI format providing the value ofPDSCH group index (g) is a second value (e.g., q=1), the UE may includethe first HARQ-ACK information and the second HARQ-ACK information formultiplexing in the PUCCH transmission occasion. For example, ifenhanced dynamic HARQ-ACK codebook is configured, a DCI (e.g., DCIformat 1_1) may indicate a number of requested groups by one bit. Forexample, the number of requested groups in the DCI may indicate value“0” to request (only) the scheduled group, and value “1” to request bothgroups. The placement of HARQ-ACK feedback for the two (or more) PDSCHgroups may be ordered based on increasing group index, e.g., when morethan one PDSCH groups are reported in a HARQ-ACK feedback report via aPUCCH. For example, if the PDSCH group index (g) is a first value (e.g.,g=1) indicating a first group index, the UE may append the firstHARQ-ACK information to the second HARQ-ACK information for multiplexingin the PUCCH transmission occasion. For example, if the PDSCH groupindex (g) is a second value (e.g., g=0) indicating a second group index,the UE may append the second HARQ-ACK information to the first HARQ-ACKinformation for multiplexing in the PUCCH transmission occasion.

The generation of the first HARQ-ACK information and/or the secondHARQ-ACK information may exclude the generation of HARQ-ACK informationfor SPS PDSCH reception(s). The UE may append the HARQ-ACK informationcorresponding to SPS PDSCH reception(s) (e.g., if any) after the firstand the second HARQ-ACK information (sub-codebooks).

FIG. 18 shows an example of grouping PDSCHs using scheduling DCIs,according to some embodiments. As shown in FIG. 18, the wireless devicemay receive an RRC message indicating a first HARQ-ACK codebook forPDSCHs. For example, the RRC message may comprise a parameter (e.g.,pdsch-HARQ-ACK-Codebook and/or pdsch-HARQ-ACK-Codebook-r16) indicatingthat the first HARQ-ACK codebook (e.g., enhanced dynamic codebook) isconfigured. The UE may receive a first DCI (DCI-1) scheduling a firstPDSCH (PDSCH-1). The first DCI may comprise a field (e.g., PDSCH groupindex) indicating that the first PDSCH is associated with a first PDSCHgroup index (e.g., group index 0, g=0). The UE may receive a second DCI(DCI-2) scheduling a second PDSCH (PDSCH-2). The second DCI may comprisea field (e.g., PDSCH group index) indicating that the second PDSCH isassociated with the first PDSCH group index (e.g., group index 0, g=0).The UE may receive a third DCI (DCI-3) scheduling a third PDSCH(PDSCH-3). The third DCI may comprise a field (e.g., PDSCH group index)indicating that the third PDSCH is associated with a second PDSCH groupindex (e.g., group index 1, g=1).

In example of FIG. 18, at least one of the three DCIs may indicate aslot for a PUCCH transmission comprising HARQ feedback information ofone or more PDSCH groups. For example, the first DCI and/or the secondDCI, that schedule PDSCHs associated with group 0, may comprise a secondfield (e.g., Number of requested PDSCH group(s), q). The second fieldmay indicate whether HARQ feedback information of only the scheduledPDSCH group (e.g., group 0) or both PDSCH groups (e.g., g=0 and g=1) isrequested in the indicated slot. For example, DCI-1 and/or DCI-2 mayindicate q=0, indicating that the HARQ feedback of the scheduled group(group 0) is requested via the indicated PUCCH transmission. The UE maymultiplex HARQ feedback information of PDSCH-1 and PDSCH-2 in theindicated PUCCH transmission occasion. The UE may determine not tomultiplex HARQ feedback of PDSCH(s) associated with the other(non-scheduled) group (e.g., group 1) in the PUCCH transmission in theslot indicated by the scheduling DCI (DCI-1 and/or DCI-2). For example,the UE may not transmit the HARQ feedback of PDSCH-3, which isassociated with group 1 (g=1), in the PUCCH transmission. For example,the third DCI may indicate a second slot for HARQ feedback transmissionof the third PDSCH. For example, the third DCI may comprise a secondfield indicating whether HARQ feedback information of only the scheduledPDSCH group (e.g., group 1) or both PDSCH groups (e.g., g=0 and g=1) isrequested in the second slot.

The UE may not expect to detect two or more DCI formats comprising/withHARQ feedback timing indicator values indicating a same slot and/or samePUCCH transmission occasion, such that the DCIs request/trigger HARQfeedback information of the scheduled group (e.g., indicate a number ofrequested PDSCH group(s) q=0), and the PDSCH group index field valuesindicated by the DCIs are different. The UE may receive the DCIsscheduling PDSCHs indicating a same slot and/or same PUCCH transmissionoccasion, such that the PDSCH group index field (g) and the number ofrequested PDSCH group(s) field (q) in the DCIs are consistent.

FIG. 19 shows an example of grouping PDSCHs using scheduling DCIs,according to some embodiments. As shown in FIG. 19, the wireless devicemay receive an RRC message indicating a first HARQ-ACK codebook forPDSCHs. For example, the RRC message may comprise a parameter (e.g.,pdsch-HARQ-ACK-Codebook and/or pdsch-HARQ-ACK-Codebook-r16) indicatingthat the first HARQ-ACK codebook (e.g., enhanced dynamic codebook) isconfigured. The UE may receive a first DCI (DCI-1) scheduling a firstPDSCH (PDSCH-1). The first DCI may comprise a field (e.g., PDSCH groupindex) indicating that the first PDSCH is associated with a first PDSCHgroup index (e.g., group index 0, g=0). The UE may receive a second DCI(DCI-2) scheduling a second PDSCH (PDSCH-2). The second DCI may comprisea field (e.g., PDSCH group index) indicating that the second PDSCH isassociated with the first PDSCH group index (e.g., group index 0, g=0).The UE may receive a third DCI (DCI-3) scheduling a third PDSCH(PDSCH-3). The third DCI may comprise a field (e.g., PDSCH group index)indicating that the third PDSCH is associated with a second PDSCH groupindex (e.g., group index 1, g=1).

In example of FIG. 19, at least one of the three DCIs may indicate aslot for a PUCCH transmission comprising HARQ feedback information ofone or more PDSCH groups. For example, the first DCI and/or the secondDCI and/or the third DCI may comprise a second field (e.g., Number ofrequested PDSCH group(s), q). The second field may indicate whether HARQfeedback information of only the scheduled PDSCH group (e.g., group 0 orgroup 1) or both PDSCH groups (e.g., g=0 and g=1) is requested in theindicated slot. For example, DCI-1 and/or DCI-2 and/or DCI-3 mayindicate q=1, indicating that the HARQ feedback of both PDSCH groups(group 0 and group 1) is requested via the indicated PUCCH transmission.The UE may multiplex HARQ feedback information of PDSCH-1 and PDSCH-2and PDSCH-3 in the indicated PUCCH transmission occasion.

A UE may postpone transmission of HARQ-ACK information corresponding toPDSCH(s) in a PUCCH for K1 values that result in a time T, being thetime between a last symbol of the PDSCH(s) and a starting symbol of thePUCCH, that is less than a required processing time for PUCCHtransmission.

The UE may receive a downlink signal (e.g. RRC and/or DCI) scheduling aPDSCH. The UE may be configured with enhanced dynamic codebook HARQfeedback operation. The PDSCH may be scheduled with a non-numericalvalue for PDSCH-to-HARQ-feedback timing, e.g. K1. The UE mayderive/determine a HARQ-ACK timing information for the PDSCH by anext/later DCI. The next DCI may be a DL DCI scheduling one or morePDSCHs. The next DCI may comprise a numerical K1 value, indicating oneor more PUCCH/PUSCH resources for HARQ feedback transmission of one ormore DL transmissions, comprising the PDSCH. The next DCI may triggerHARQ feedback transmission for one or more PDSCH groups comprising agroup of the PDSCH. The UE may derive/determine the HARQ-ACK timinginformation for the PDSCH by a last/earlier DCI.

The UE may receive a first DCI scheduling a PDSCH with non-numerical K1value. For (non-enhanced) dynamic HARQ-ACK codebook, the UE maydetermine/derive a HARQ-ACK timing for the PDSCH scheduled withnon-numerical K1 value, by a second DCI. The second DCI may schedule asecond PDSCH with a numerical K1 value. The UE may receive the secondDCI after the first DCI.

The base station may transmit a DCI requesting/triggering HARQ feedbackof a HARQ-ACK codebook containing one or more or all, DL HARQ processes(e.g., one-shot feedback request). The one-shot feedback request may befor one or more or all component carriers configured for the UE.One-shot feedback may be configured separately from a HARQ-ACK codebookconfiguration.

The wireless device may transmit HARQ feedback of one or more PDSCHs inresponse to receiving a one-shot feedback request. A last/latest PDSCHfor which an acknowledgment is reported in response to receiving theone-shot feedback request, may be determined as a last PDSCH within a UEprocessing time capability (e.g. baseline capability, N1). The UE mayreport HARQ-ACK feedback for one or more earlier PDSCHs scheduled withnon-numerical K1 value. The one-shot feedback may be requested in aUE-specific DCI. The one-shot feedback may request HARQ feedbacks to bereported in a PUCCH. The HARQ feedback may be piggybacked on/multiplexedin a PUSCH.

The wireless device may be configured to monitor feedback request forone-shot HARQ-ACK codebook feedback. The feedback may be requested in aDCI format (e.g., DCI format 1_1). The DCI format may or may notschedule DL transmission (e.g., PDSCH). The DCI format may comprise afirst field (e.g., a frequency domain resource allocation field)indicating a first value. The UE may determine that the DCI format doesnot schedule a PDSCH in response to the first field indicating the firstvalue. The UE may ignore/discard one or more second fields of the DCIformat (e.g., a HARQ process number and/or NDI field) in response to thedetermining. The UE may be scheduled to report one-shot feedback and oneor more other HARQ-ACK feedbacks in a same slot/subframe/resource, andthe UE may report only the one-shot feedback.

In a one-shot codebook, one or more NDI bits may follow one or moreHARQ-ACK information bits for each of one or more TB s. The HARQ-ACKinformation bits and the corresponding NDI may be ordered in theone-shot codebook as follows: first in an increasing order of CBG index,second in an increasing order of TB index, third in an increasing orderof HARQ process ID, and fourth in an increasing order of serving cellindex.

The wireless device may transmit the HARQ-ACK for a PDSCH, that isscheduled with non-numerical K1 value, via one-shot HARQ feedback. Thewireless device may not include the HARQ-ACK for a PDSCH, that isscheduled with non-numerical K1 value, in a semi-static codebook. Thewireless device may include the HARQ-ACK for a PDSCH, that is scheduledwith non-numerical K1 value, in a semi-static codebook. With semi-staticcodebook, HARQ-ACK timing for a PDSCH scheduled with a non-numerical K1may be derived based on the next DL DCI scheduling PDSCH with anumerical K1 value. A wireless device may report HARQ-ACK in theappended bit container. With dynamic codebook, HARQ-ACK timing for aPDSCH scheduled with DCI indicting a non-numerical K1 may be derivedbased on the next DCI scheduling PDSCH with a numerical K1 value. Thewireless device may expect that DAI is reset for PDSCH transmitted laterthan N1 symbols before PUCCH transmission.

A base station may schedule multiple Transmission Time Intervals (TTIs)for multiple uplink (e.g., PUSCH) transmissions, also referred to asmulti-TTI scheduling. For example, each TTI may be scheduled using aseparate UL grant (e.g., multiple DCIs) in the same PDCCH monitoringoccasion. In another example, a base station may schedule multiple TTIsfor multiple PUSCH transmissions, using a single UL grant (e.g., singleDCI). For example, multiple (e.g., different) TBs with different HARQprocess IDs may be scheduled over the multiple TTIs (e.g., multipleslots/mini-slots/subslots/subframes). For example, a first (same) TBassociated with a first HARQ process ID may be scheduled over themultiple TTIs (e.g., for multiple repetitions) using a single UL grant.The UE may rate-match the first TB across all TTIs. The UE may transmitthe first TB with one or more (e.g. different) RVs in different TTIs.

In an example, a TTI may be a subframe, and/or one or more slots, and/orone or more mini-slots. A slot may comprise, e.g., 14 consecutive OFDMsymbols. A mini-slot may comprise, e.g., one or more consecutive OFDMsymbols, which may be shorter than a slot.

A wireless device may receive one or more RRC messages comprisingconfiguration parameters of one or more PUSCH configurations for atleast one BWP of a serving cell. A PUSCH configuration may comprise aPUSCH time domain resource allocation (TDRA) list for a DCI format (e.g.PUSCH-TimeDomainResourceAllocationListForDCI-Format0-1,PUSCH-TimeDomainResourceAllocationListForDCI-Format0-2). A PUSCH TDRAlist may be used to configure a time domain relation between PDCCHassociated with a reception of the DCI format and the PUSCH(s) scheduledby the DCI format. The PUSCH TDRA list may comprise one or more TDRAvalues (e.g. up to 8). Each TDRA value may indicate time domainscheduling parameters for a PUSCH, e.g. a slot offset (K2) from thePDCCH; a PUSCH mapping type; a starting symbol and length (SLIV) or astarting symbol (S) and a symbol duration of the PUSCH (L); and a numberof repetitions. The network may indicate in an uplink grant in the DCIformat which of the configured TDRA value(s) in the PUSCH TDRA list thewireless device may apply for the UL grant. The wireless device maydetermine a bit width of the DCI field (TDRA field in the DCI format)based on a number of entries in the RRC parameter, e.g. the PUSCH TDRAlist configured by RRC. A first value in the DCI field may refer to afirst entry/element in this RRC list.

A base station may transmit a DCI format to schedule uplinktransmission, e.g., PUSCH, in each of one or more transmission timeintervals (TTIs) for a UE, e.g. in an unlicensed cell (e.g., LicenseAssisted Access (LAA) SCell and/or NR-U PCell). For example, DCI formatOB is used for scheduling of PUSCH in each of multiple subframes in aLAA SCell. In another example, DCI format 4B may be used for schedulingof PUSCH with multi-antenna port transmission mode in each of multiplesubframes in a LAA SCell. Such DCI format may be referred to a multi-TTIDCI format.

A multi-TTI DCI format may comprise at least the following information:identifier for DCI formats; carrier indicator; downlink feedbackindication (DFI) flag, if the wireless device is configured foroperation in a cell with shared spectrum channel access (unlicensedspectrum). In an example, the DCI format may not be for indicatingdownlink feedback, e.g. the DFI is zero. In an example, the DCI formatmay be used for scheduling one or multiple PUSCH in at least one cell(e.g. multi-TTI scheduling) and/or activating type 2 configured granttransmission. In the example, the DCI format may comprise at least thefollowing information: UL/SUL indicator; BWP indicator; frequency domainresource assignment (FDRA); one or more time domain resource assignments(TDRA) values for the one or more PUSCHs scheduled by the DCI format; amodulation and coding scheme for the one or more PUSCHs; one or more newdata indicators (NDIs) for the one or more PUSCHs; one or moreredundancy versions (RVs) for the one or more PUSCHs; a HARQ processnumber/ID for a first PUSCH of the one or more PUSCHs; at least onedownlink assignment index (DAI); CSI request; CBG transmissioninformation; a beta-offset indicator indicating one or more beta-offsetvalues for one or more UCI types comprising HARQ-ACK and/or SR and/orCSI report; a channel access CP extension and/or channel access priorityclass (CAPC); etc.

In an example, for multi-TTI scheduling and/or single-TTI scheduling forPUSCH, a wireless device may attempt transmitting a PUSCH at a singlestarting position indicated in the UL grant for this PUSCH.

The base station may schedule time-contiguous transmissions of multiplePUSCHs. The base station may schedule non-time-contiguous transmissionsof multiple PUSCHs. For example, multi-TTI scheduling by a single DCImay schedule a plurality of consecutive TTIs. For example, in multi-TTIscheduling, the base station may schedule a plurality of PUSCHs that arecontinuous in time. A single PUSCH duration may not exceed 14 OFDMsymbols. In an example, each PUSCH may be mapped to one slot and/or onemini-slots. In another example, each PUSCH may be mapped to one or moreslots and/or one or more mini-slots, e.g., the one or more slots and/orthe one or more mini-slots may be consecutive.

Multiple PUSCHs scheduled by the multi-TTI DCI may be contiguous. Forexample, the network may configure/indicate the TDRA values in the DCIsuch that the scheduled PUSCHs are contiguous in time. The TDRAlist/table configuration (RRC configuration) may allow indicating singleor multiple continuous PUSCHs in any slot of the multiple scheduledslots. Each entry/row of the TDRA table/list indicates a number ofscheduled PUSCHs by a single DCI. For example, a number of scheduledPUSCHs may be signaled by a number of indicated valid SLIVs in therow/entry/element of the configured PUSCH TDRA list that issignaled/indicated in the scheduling DCI. For example, if the RRCconfiguration of PUSCH TDRA list (e.g.PUSCH-TimeDomainResourceAllocationList) comprises a row/entry/elementindicating TDRA value for multiple contiguous PUSCHs, the slot offset(K2) may indicate the slot where the wireless device may transmit thefirst PUSCH of the multiple PUSCHs. Each PUSCH may have a separatestarting symbol and length (e.g. SLIV) and/or mapping type.

The base station may schedule discontinuous HARQ IDs for schedulingmultiple TBs with different HARQ process IDs in multiple TTIs. The basemay indicate in the multi-TTI scheduling DCI a HARQ process ID to beapplied to the first scheduled PUSCH, e.g., for the first TTI. Forexample, the HARQ process ID may be incremented by 1 for subsequentPUSCHs in the scheduled order. For example, modulo operation may be usedif the number of scheduled PUSCHs are more than the available/configurednumber of HARQ IDs.

The base station may signal at least the following information in a DCIscheduling multiple PUSCHs: NDI field with 1 NDI bit per PUSCH; RV fieldwith one or more RV bits per PUSCH; CBGTI field, e.g., per retransmittedPUSCH and/or per PUSCH and/or for a number of PUSCHs; HARQ process ID ofa first PUSCH; time domain resource assignment (TDRA) field; CSI requestfield, e.g., for a single PUSCH; MCS field; LBT (channel access) type;channel access priority class (CAPC); etc.

The multi-TTI DCI may comprise a MCS field indicating one or more MCSindexes (e.g. entry/row of an MCS table). For example, a single MCSindex may be signaled for the multiple scheduled PUSCHs. For example,the UE may apply the same behavior for a first PUSCH scheduled forinitial transmission and a second PUSCH scheduled for retransmission.For example, the behavior may be: determining the TB size based onexplicitly indicated MCS (e.g., for MCS row 0-27); and/or referring tothe DCI scheduling the initial PUSCH transmission to determine the TBsize (e.g., for MCS row 28-31). In an example, a single MCS (e.g., row0-27) may be indicated in the multi-TTI DCI. For example, the UE mayapply different behavior for a first PUSCH scheduled for initialtransmission and a second PUSCH scheduled for retransmission. Forexample, for the first PUSCH scheduled for initial transmission, the UEmay determine the TB size based on the indicated MCS. For example, forthe second PUSCH scheduled for retransmission, the UE may refer to theDCI scheduling the initial PUSCH transmission to determine the TB size.For example, the UE may not expect to receive signaling of a MCS row28-31 in a multi-TTI DCI. In another example, the MCS field of themulti-TTI DCI may comprise a bitmap. The UE may use the bitmap todetermine one or more first PUSCHs to use the indicated MCS row, and oneor more second PUSCHs to use a MCS row indicated by the previous DCIscheduling the same TB.

In an example, a multi-TTI DCI may indicate a CSI report request. Forexample, a DCI scheduling multiple PUSCHs may request a CSI reporttransmission. The wireless device may determine a first PUSCH/slot fromthe multiple PUSCHs/scheduled slots for transmission of the CSI report.For example, the wireless device may determine a last or a second lastPUSCH/slot to transmit the CSI report. For example, the wireless devicemay determine the last PUSCH/slot to transmit the CSI report, if thenumber of scheduled PUSCHs is not more than two. For example, thewireless device may determine the second last (the one before the last)PUSCH/slot to transmit the CSI report, if the number of scheduled PUSCHsis more than two.

For a multi-TTI grant, a wireless device may map generated transportblocks (TBs) internally to different HARQ processes, e.g. in case of LBTfailure(s). For example, the wireless device may transmit a TB, pendingfor transmission in a first HARQ process due to a failed LBT for a firstPUSCH transmission associated with the first HARQ process, in a secondHARQ process. For example, the second HARQ process may be associatedwith a second PUSCH for which LBT is successful. The TB may be a new TB,e.g. pending/ready for initial transmission. The wireless device maytransmit a new TB on any HARQ process of the multi-TTI grant associatedwith a second PUSCH. The second PUSCH may have a same TB size (TBS)and/or same RV as the first PUSCH. The NDI of the second PUSCH mayindicate a new transmission. The second PUSCH may not be scheduled for aHARQ process that is associated with a retransmission, otherwise anambiguity between the wireless device and the base station may occur inidentifying the TBs across HARQ processes. So, this may only apply toHARQ processes that are associated with initial transmissions, indicatedby the corresponding NDI bit(s).

The existing technology defines frequency ranges for wireless operation.For example, NR Rel-15 and Rel-16 define two frequency ranges (FRs): FR1spanning from 410 MHz to 7.125 GHz and FR2 spanning from 24.25 GHz to52.6 GHz. Recent studies reveal a global availability of bands beyondthe currently operational frequency ranges, e.g., in the 52.6 GHz to 71GHz range. The proximity of the higher frequency range to FR2 and theimminent commercial opportunities for high data rate communication makesit compelling for wireless technologies to address operation (e.g., NRoperation) in this frequency regime. For example, 3GPP has decided toextend FR2 operation up to 71 GHz, considering both licensed andunlicensed operation, with the adoption of one or more new numerologies(e.g., larger subcarrier spacings). These high frequency bands compriseunlicensed bands (e.g., unlicensed 60 GHz band). Existing procedures(e.g., LAA/NR-U defined procedures) for operation in unlicensed spectrummay be leveraged towards operation in these high frequency unlicensedbands. For channel access, both LBT mode and no-LBT mode may besupported to cover a wide range of use cases and regulatoryrequirements.

Supporting larger subcarrier spacings (e.g., 120 KHz, 240 KHz, 480 KHz,and 960 KHz) may require enhancements of some existing processingtimelines; e.g., processing capability for PUSCH scheduled by RAR ULgrant; dynamic SFI and SPS/CG cancellation timing; timeline for HARQ-ACKinformation in response to a SPS PDSCH release/dormancy; minimum timegap for wake-up and SCell dormancy indication; BWP switch delay;multi-beam operation timing (timeDurationForQCL, beamSwitchTiming, beamswitch gap, beamReportTiming, etc.); timeline for multiplexing multipleUCI types; minimum of P_switch for search space set group switching;appropriate configuration(s) of scheduling time offsets such as k0 (forPDSCH), k1 (for HARQ), k2 (for PUSCH); PDSCH processing time (N1), PUSCHpreparation time (N2), HARQ-ACK multiplexing timeline (N3); CSIprocessing time, Z1, Z2, and Z3, and CSI processing units; potentialenhancements to CPU occupation calculation; related UE capability(ies)for processing timelines; minimum guard period between two SRS resourcesof an SRS resource set for antenna switching.

Due to higher processing requirements in these high frequency bands andmuch shorter slot durations, limitations to PDCCH monitoring may beconsidered. For example, increased minimum PDCCH monitoring unit may besupported to help with UE processing. Time domain schedulingenhancements for PDSCH/PUSCH may be supported, e.g., increasing minimumtime-domain scheduling unit to be larger than one symbol, multi-PDSCHscheduled by one DCI (multi-TTI scheduling), mapping one TB to multipleslots (e.g., TTI bundling), etc. Scheduling each PUSCH and/or PDSCH viaa separate DCI may waste resources, because many of the signaledparameters may be redundant across the respective DCIs. For example,multiple PDSCH/PUSCH (PxSCH) scheduling with a single DCI (usingexisting DCI formats or new DCI format(s)) may be supported to reducescheduling overhead as well as PDCCH monitoring requirements in timedomain.

For a wireless device and a serving cell, scheduling multiple PDSCHs bya single DL DCI and scheduling multiple PUSCHs by a single UL DCI may besupported. Each PDSCH/PUSCH may have individual/separate TB(s). EachPDSCH/PUSCH may be confined within a slot. A maximum number of M PDSCHsor PUSCHs may be scheduled with a single DCI (e.g., M=8 or 16 or 32).For multi-PUSCH/PDSCH scheduling, a TDRA table may be configured suchthat each row indicates up to X multiple PUSCHs/PDSCHs, which may becontinuous and/or non-continuous in time domain. Each PUSCH/PDSCH mayhave a separate SLIV and mapping type. A number of the scheduledPUSCHs/PDSCHs (X) may be signaled by a number of indicated valid SLIVsin the row of the TDRA table signaled in the DCI. The TDRA table may beconfigured such that each row indicates up to X (e.g. 8) PUSCH/PDSCHgroups. The PUSCH/PDSCH groups may be non-continuous. Each PUSCH/PDSCHgroup may have a separate SLIV, mapping type, and/or number of slots orPUSCHs/PDSCHs (N). Within each group, N PUSCHs/PDSHCs may occupy thesame OFDM symbols indicated by the SLIV and mapping type. A number ofscheduled PUSCHs/PDSCHs may be the sum of number of PUSCHs/PDSCHs in allPUSCH/PDSCH groups in the row of the TDRA table signaled in DCI (e.g., 1to M).

For multi-PUSCH/PDSCH scheduling, CBG (re)transmission may or may not besupported. Ultra Reliable Low Latency Communications (URLLC) relatedfields such as priority indicator and/or open-loop power controlparameter set may be indicated in the DCI for multiple scheduledPUSCHs/PDSCHs. For multiple PUSCHs/PDSCHs scheduled by a single DCI, NDIand/or RV may be signaled per PUSCH/PDSCH. A number of NDI bits and/orRV bits in the DCI may be determined based on the configured TDRA table.HARQ process ID signaled in the DCI may apply to a first scheduledPUSCH/PDSCH of the multiple PUSCHs/PDSCHs scheduled by the DCI. HARQprocess ID may be incremented by 1 for subsequent PUSCHs/PDSCHs in thescheduled order (with modulo operation as needed). Same FDRA and/or MCSvalue indicated by the DCI may be applied to all scheduledPUSCHs/PDSCHs.

For a DCI scheduling multiple PDSCHs, a slot offset k0 (indicated by theTDRA field in the DCI) may indicate a gap between a slot of thescheduling DCI (e.g., the PDCCH reception slot) and a first slot of themultiple slots of PDSCHs scheduled by the DCI. For example, k0 mayindicate the slot offset between the DCI and an earliest PDSCH scheduledby the DCI.

For multi-PDSCH scheduling, multiple HARQ-ACKs corresponding to themulti-PDSCHs may be fed back. For a DCI scheduling multiple PDSCHs,HARQ-ACK information corresponding to PDSCHs scheduled by the DCI may bemultiplexed in a single PUCCH in a first slot. The first slot may bedetermined based on a first offset, K1. The first offset may beindicated by the DCI, e.g., by a PDSCH-to-HARQ_feedback timing indicatorfield in the DCI. The first offset may be indicated by RRC signaling,e.g., provided by dl-DataToUL-ACK if the PDSCH-to-HARQ_feedback timingindicator field is not present in the DCI. The first offset (K1) mayindicate a slot offset between a slot of a last PDSCH scheduled by theDCI and a slot carrying the HARQ-ACK information corresponding to thescheduled PDSCHs.

FIG. 20 shows an example of HARQ-ACK transmission associated with a DCIscheduling multiple PDSCHs, according to some embodiments. As shown inthe figure, the DCI indicates a k0 slot offset and a k1 slot offset. Thewireless device determines a first slot associated with a first PDSCH ofthe multiple scheduled PDSCHs (PDSCH 1) by applying the k0 slot offsetto a slot where the DCI is received. The wireless device determines anumber of scheduled PDSCHs based on the DCI, e.g., the TDRA field in theDCI. In this figure, the wireless device determines four PDSCHsscheduled by the DCI. The multiple PDSCHs may be scheduled in one ormore slots starting from the first slot indicated by the k0 slot offset.The multiple PDSCHs may be in consecutive slots. The multiple PDSCHs maybe continuous and/or discontinuous, e.g., a non-zero gap may or may notbe between adjacent PDSCHs scheduled by the DCI. A gap may comprise zeroor more symbols and/or slots. The wireless device may determine a secondslot for HARQ-ACK transmission of the multiple PDSCHs via a PUCCH basedon the k1 slot offset. The wireless device may apply the k1 slot offsetto a slot of the last scheduled PDSCH (PDSCH 4) to determine the secondslot. The wireless device may transmit HARQ-ACK information associatedwith all the scheduled PDSCHs via the PUCCH resource in the second slot.

A PDSCH processing time may be considered, e.g., a first symbol of thePUCCH comprising the HARQ-ACK information of PDSCHs scheduled by theDCI, may not start earlier than a time gap after a last symbol of aPDSCH reception associated with the HARQ-ACK information (e.g., the lastPDSCH). The time gap may be given by the UE PDSCH processing capabilityin the corresponding frequency band.

In an example, a scheduler (e.g., base station) may be prohibited toindicate a HARQ feedback timing earlier than a PDSCH processing time fora last PDSCH of the multi-PDSCH scheduled by a single DCI. However,flexibility of HARQ feedback scheduling may be degraded. Moreover, animpact on HARQ feedback latency especially for the earliest scheduledPDSCHs may be problematic, e.g., for URLLC traffic.

In an example, HARQ-ACK information corresponding to different PDSCHsscheduled by a single DCI may be carried by different PUCCH(s), e.g., indifferent slots. In an example, the DCI may indicate HARQ-ACK timingearlier than the PDSCH processing time for the last PDSCH(s). In anexample, the wireless device may postpone HARQ feedback of one or moreof the multiple PDSCHs scheduled by a DCI. The base station may triggerfeedback of the postponed HARQ-ACKs later, e.g., using a second DCI (asin non-numerical K1 indication).

In existing technologies, a wireless device may receive a DCI that mayschedule a single PDSCH. The DCI may indicate a single PDSCH group indexfor the scheduled PDSCH, e.g., if an enhanced dynamic codebook isconfigured. The DCI may or may not indicate a slot for HARQ feedbacktransmission associated with the scheduled PDSCH. The DCI may comprise afield (e.g., a number of requested PDSCH group(s)), indicatingwhether: 1) only HARQ feedback information of the scheduled PDSCH groupis requested via an indicated PUCCH transmission occasions, or 2) HARQfeedback information of the scheduled PDSCH group and a non-scheduledPDSCH group is requested via an indicated PUCCH transmission occasions.

FIG. 21A and FIG. 21B show an example of requesting HARQ feedback of oneor more PDSCH groups, according to some embodiments. As shown in thefigures, a downlink DCI may schedule a PDSCH. The DCI may comprise afield indicating a PDSCH group index (g=0 or 1) for the scheduled PDSCH.The DCI may comprise a second field indicating one or more requestedPDSCH group(s). The wireless device may determine to transmit/reportHARQ feedback of a first PDSCH group and/or a second PDSCH group, basedon the second field. The reported PDSCH group may depend on thescheduled PDSCH group (g). For example, as shown in the table of FIG.21B, a first value of the second field (number of requested PDSCH groupsbeing 0) may indicate that HARQ feedback of PDSCH(s) of a PDSCH groupassociated with the scheduled PDSCH group (g) is requested. A secondvalue of the second field (number of requested PDSCH groups being 1) mayindicate that HARQ feedback of PDSCH(s) of both PDSCH groups (e.g.,group 0 and group 0) are requested.

With the introduction of multi-PDSCH scheduling, a DCI may schedule morethan one PDSCHs. The existing technologies may not be sufficient forrequesting/triggering HARQ feedback information in multi-PDSCHscheduling. The multiple PDSCHs scheduled by the DCI may comprisemultiple transport blocks (TBs). For example, each of the multiplePDSCHs may comprise a different TB. In an example, different TBs maycorrespond to different PDSCH groups. For example, a first PDSCH of themultiple PDSCHs may correspond to a retransmission of a first TBassociated with a first DL HARQ process. For example, a firsttransmission of the first TB may have been associated with a PDSCH of afirst PDSCH group index (e.g., group 1). For example, the retransmissionof the first TB may also be associated with PDSCH of the first PDSCHgroup index. For example, a second PDSCH of the multiple PDSCHs maycorrespond to a retransmission of a second TB associated with a secondDL HARQ process. For example, a first transmission of the second TB mayhave been associated with a PDSCH of a second PDSCH group index (e.g.,group 0). For example, the retransmission of the second TB may also beassociated with PDSCH of the second PDSCH group index. Thus, forenhanced scheduling flexibility and efficient resource utilization, thebase station may indicate different PDSCHs, scheduled by a same DCI, tobe associated with different PDSCH groups/group indexes. For example,the DCI may indicate one or more first PDSCHs of the multiple PDSCHs tobe associated with a first PDSCH group index, and one or more secondPDSCHs of the multiple PDSCHs to be associated with a second PDSCH groupindex.

However, based on the existing technologies, the DCI format may notenable requesting HARQ feedback information of either of the scheduledPDSCH groups, because previously, only one PDSCH group was scheduled bya DCI. This may result in increased restrictions in triggering HARQfeedback transmissions in one or more cells. For example, the DCI mayschedule PDSCHs associated with two or more PDSCH groups, and it isdesirable for increased flexibility of the scheduler that the DCI canrequest HARQ feedback for either of the PDSCH groups and/or both/all ofthem. Existing DCI formats may not provide a mechanism to enable thisgoal.

For example, in high frequencies where slot durations are considerablyshort, a PDCCH monitoring of the UE may be reduced in time domain, and aDCI detected/received in a slot may schedule considerably large numberof PDSCHs (e.g., up to 16 or 32 or more) over large number of slots in acell. The PDSCHs may be of a first PDSCH group and a second PDSCH group.In an example, one or more PUCCH transmission occasions may be availableon one or more uplink carriers for HARQ feedback transmission of one ormore PDSCHs scheduled by the DCI. The available PUCCH transmissionoccasion(s) may be triggered/indicated by a second DCI (e.g., in same oranother cell), for a first PDSCH group (e.g., group 0 or group 1). It isdesired that the first DCI, scheduling the one or more PDSCHs cantrigger HARQ feedback of the one or more PDSCHs via the available PUCCHtransmission occasion(s). To this end, the DCI may indicate a request ofthe same PDSCH group as the PUCCH transmission occasion. The one or morePDSCHs may be associated with the first PDSCH group and/or a secondPDSCH group. A mechanism is needed to enable the scheduling DCI totrigger HARQ feedback information of a PDSCH group, among two or morescheduled PDSCH groups, based on the availability of the scheduledresources. For example, in response to the available PUCCH transmissionoccasion(s) being associated with the first PDSCH group index, it isdesired that the scheduling DCI can request HARQ feedback of thosePDSCHs that are associated with the first PDSCH group, although the DCImay schedule PDSCHs associated with both PDSCH groups. For example, theDCI may request HARQ feedback of other scheduled PDSCHs that areassociated with the second PDSCH group via a second PUCCH transmissionoccasion, e.g., in another slot, wherein the second PUCCH transmissionoccasion is associated with the second PDSCH group. Thus, efficientutilization of UL resources for timely HARQ feedback transmission ofmultiple PDSCHs scheduled by a DCI may be enabled. Embodiments mayprovide one or more mechanisms to achieve the desirable flexibility andefficiency in a multi-PDSCH scheduling scenario.

In an example, a DCI scheduling multiple PDSCHs may comprise a fieldindicating two or more slots for HARQ feedback transmission. Forexample, the DCI may indicate two or more PUCCH transmission occasionsfor HARQ feedback transmission of the multiple PDSCHs. It may bedesired, for increased scheduling flexibility and efficient resourceutilization, and based on the available/scheduled traffic and/orallocated resources, that the base station can independently requestHARQ feedback of different PDSCH group(s) for the two or more PUCCHtransmission occasions. For example, the base station may need torequest HARQ feedback for a first PDSCH group via the first PUCCHtransmission occasions, and request HARQ feedback for a second PDSCHgroup (and the first PDSCH group) via the second PUCCH transmissionoccasions. For example, the first PUCCH transmission may be availablefor/associated with a first or second PDSCH group, while the secondPUCCH transmission occasion may be available for/associated with bothPDSCH groups. Based on the existing technologies, the DCI may not beable to indicate the requested PDSCH group(s) for each of the indicatedPUCCH transmission occasions independently and/or flexibly. To improveon existing technologies, some embodiments may enable such indication ina multi-PDSCH scheduling DCI, and thus, improve the schedulingflexibility and resource utilization in a wireless network, whileestablishing a common understanding between the wireless device and thebase station about mapping the indicated slots to requested PDSCHgroup(s).

Per one or more embodiments of the present disclosure, a wireless devicemay receive one or more RRC messages from a base station. The one ormore RRC messages may comprise at least one system information block,e.g., SIB1 and/or an extra SIB-1 an/r SIB-2, etc. The one or more RRCmessages may comprise configuration parameters of one or more servingcells. The one or more serving cells may comprise a primary cell and/orat least one secondary cell of a master cell group and/or a secondarycell group. The one or more serving cells may be activated. The one ormore serving cells may comprise downlink carrier and/or uplink carrier.The one or more serving cells may comprise a first uplink carrier (e.g.,normal UL—NUL) and/or a second uplink carrier (e.g., supplementaryUL—SUL).

The configuration parameters may indicate one or more DL BWPs for adownlink carrier/cell. A first DL BWP may be active DL BWP of the cell.The configuration parameters may indicate a first SCS for the first DLBWP. For example, the base station may configure different DL BWPs of asame cell or different cells with same or different SCSs.

The configuration parameters may indicate one or more search spaces fora DL BWP of a cell. The one or more search spaces may comprise PDCCHmonitoring occasions/candidates. For example, the configurationparameters may indicate: a monitoring slot periodicity; a monitoringslot offset; a duration for each occurrence upon every period (number ofconsecutive slots); monitoring symbols within a monitoring slot; and anumber of candidates (e.g., aggregation level). In an example, theconfiguration parameters of the search spaces may indicate a smallernumber of candidate PDCCHs in time domain (e.g., in a frame duration),such that sparser/less often monitoring is needed at the UE side. In anexample, a first SCS of a first DL BWP associated with the search spacesmay be large (e.g., 480 KHz or 960 KHz). In an example, a second SCS ofa second DL/UL carrier for which the PDCCH can schedulereceptions/transmissions (e.g., cross-carrier scheduling) may be large,e.g., larger than the first SCS of the DL BWP associated with the searchspace.

The configuration parameters may comprise PDSCH configuration parametersfor a DL BWP of a cell. The PDSCH configuration parameters may indicatea time domain resource allocation (TDRA) table/list for scheduling PDSCHon the corresponding DL BWP. The PDSCH configuration parameters mayindicate a number of PDSCHs (e.g., a maximum number) that a single DCImay schedule for a cell at the same time. In an example, the wirelessdevice may determine a bit width (size) of a DCI field based on thenumber of entries in the TDRA table/list. A first value in the DCI fieldmay refer to a first element/entry/row in the TDRA table/list. Forexample, an element/entry/row of the TDRA table may indicate a firstslot offset from the scheduling DCI to the PDSCH (k0), a PDSCH mappingtype, a starting symbol in the slot and a length (e.g., number ofsymbols from the starting symbol—SLIV), and/or a repetition number. Inan example, a number of valid entries in a row of the TDRA table (e.g.,valid SLIVs) may indicate a number of PDSCHs scheduled by the DCI. Forexample, in the example of FIG. 20, the DCI may indicate a TDRA valuethat indicates four PDSCHs in four consecutive slots. The PDSCHs may ormay not be contiguous. For example, the TDRA value may indicate zero ornon-zero gaps between two PDSCHs.

The configuration parameters may indicate one or more UL BWPs for anuplink carrier of a cell. A first UL BWP may be active UL BWP of thecarrier. The configuration parameters may indicate a first SCS for thefirst UL BWP. For example, the base station may configure different ULBWPs of a same carrier/cell or different carriers/cells with same ordifferent SCSs.

The configuration parameters may comprise one or more PUCCHconfigurations. The one or more PUCCH configurations may indicate one ormore PUCCH resources on an UL BWP of an UL carrier/cell. A PUCCHconfiguration may indicate one or more PUCCH resource sets, eachcomprising one or more PUCCH resources. The configuration parameters mayindicate for each PUCCH resource an ID, a starting PRB, a frequencyhopping indication, and a PUCCH format (e.g., format 0, 1, 2, 3, or 4).The configuration parameters may indicate for each PUCCH format aninitial cyclic shift, a number of symbols, a starting symbol indexwithin a slot, and/or a number of PRBs. The configuration parameters mayindicate a list of timing values for a given PDSCH to the DL ACK (e.g.,HARQ-ACK—dl-DataToUL-ACK/dl-DataToUL-ACK-r16/dl-DataToUL-ACK-DCI-1-2-r16).For example, the list of timing values for PDSCH to DL ACK may comprisea plurality of value (e.g., up to 8 or 16 values) from a set of integers(e.g., −1 to 15 or 31). In an example, the value −1 may correspond to“non-numerical value” for the case where the ACK/NACK feedback timing isnot explicitly included at the time of scheduling PDSCH.

In an example, the wireless device may monitor one or more PDCCHcandidates of a search space. The wireless device may monitor the one ormore PDCCH candidates for a DCI with a first size. The wireless devicemay determine the size of the DCI based on the configuration parametersreceived via RRC message(s). The wireless device may receive the DCI ina PDCCH monitoring occasion.

The DCI may schedule multiple PDSCHs. For example, the DCI may comprisea time domain resource assignment (TDRA) field indicating multiple timeresources (e.g., SLIVs) for the multiple PDSCHs. The DCI may indicate anoffset (k0) to a first slot of a first PDSCH of the multiple PDSCHs. Themultiple PDSCHs may be scheduled in consecutive slots starting from thefirst slot (e.g., as shown in FIG. 20). The multiple PDSCHs may bescheduled in non-consecutive slots. The multiple PDSCHs may becontiguous in time domain (e.g., no gap between two PDSCHs of themultiple PDSCHs). The multiple PDSCHs may be non-contiguous in timedomain (e.g., one or more symbols/slots of gap between at least twoPDSCHs of the multiple PDSCHs).

The DCI may comprise a field (e.g., PDSCH-to-HARQ-feedback timingindicator) indicating a slot offset for HARQ feedback transmission ofone or more PDSCHs scheduled by the DCI. The wireless device maydetermine a bit width/size of the field based on a number of entries ina higher layer parameter, for example, a first configuration parameterindicated by RRC message(s) (e.g., dl-DataToUL-ACK list/table). Thefield may indicate a first slot offset value (k1). The wireless devicemay determine a slot for PUCCH transmission comprising HARQ feedback ofthe PDSCHs based on the first slot offset value (k1). FIG. 20 shows anexample of using the slot offset in a multi-PDSCH scheduling scenario.

In an example, the wireless device may receive an RRC message comprisingconfiguration parameters of a cell (e.g., PhysicalCellGroupConfig). Theconfiguration parameters may comprise at least a first parameter (e.g.,pdsch-HARQ-ACK-Codebook-r16, and/or pdsch-HARQ-ACK-CodebookList-r16)that indicates a first HARQ-ACK codebook for PDSCHs of the cell. Thefirst HARQ-ACK codebook may be an enhanced dynamic codebook (e.g.,enhanced Type-2 codebook). In response to configuring the first HARQ-ACKcodebook, the wireless device and/or the base station may group PDSCHsand respective HARQ feedback information. For example, the wirelessdevice may determine that a PDSCH is associated with a first PDSCHgroup. For example, s DCI scheduling the PDSCH may comprise a PDSCHgroup index indicating a first PDSCH group index value. The wirelessdevice may determine, based on the PDSCH group index, that the PDSCH isassociated with a first PDSCH group. The wireless device may determine,based on a second PDSCH group index, that a second PDSCH is associatedwith a second PDSCH group.

In response to configuring the first HARQ-ACK codebook, the wirelessdevice may determine size/bit-width of at least one field in a DCIscheduling multiple PDSCHs. For example, the wireless device may receivea DCI scheduling multiple (e.g., a plurality of) PDSCHs. For example, afield in the DCI format may indicate that each of the multiple PDSCHsare associated with which PDSCH group (e.g., PDSCH group index). Forexample, the field may indicate whether a first PDSCH of the multiplePDSCHs is associated with a first PDSCH group or a second PDSCH group.For example, the field may indicate whether a second PDSCH of themultiple PDSCHs is associated with a first PDSCH group or a second PDSCHgroup, and so on.

In an example, the multiple PDSCHs may be associated with a same (e.g.,first or second) PDSCH group. For example, the RRC parameters maycomprise a parameter indicating whether the multiple PDSCHs scheduled bya DCI may or may not be associated with different PDSCH groups. Forexample, the wireless device may determine a size of the DCI fieldindicating PDSCH group index(es) of the multiple PDSCHs based on theparameter. For example, if the parameter is (not) configured and/orindicates a first value, the wireless device may determine a first valuefor the size of the DCI field. For example, if the parameter isconfigured and/or indicates a second value, the wireless device maydetermine a second value for the size of the DCI field.

For example, the RRC parameter may indicate that multiple PDSCHsscheduled by a DCI may be associated with a same PDSCH group. The DCImay comprise a field indicating PDSCH group indexes for the scheduledmultiple PDSCHs. The wireless device may determine that the size of thefield in the DCI scheduling the multiple PDSCHs is a first value (e.g.,one bit indicating PDSCH group index 0 or 1). For example, the RRCparameter may indicate that multiple PDSCHs scheduled by a DCI may beassociated with different PDSCH groups. The wireless device maydetermine that the size of the field in the DCI scheduling the multiplePDSCHs is a second value (e.g., one bit indicating PDSCH group index 0or 1). For example, the DCI field may be a bitmap, wherein each bit inthe bitmap may indicate a PDSCH group index (e.g., 0 or 1) for arespective PDSCH. for example, the size of the bitmap may be pre-definedand/or pre-configured. For example, the wireless device may determinethe size of the field based on a (maximum) number of multiple PDSCHsscheduled by a DCI. For example, the wireless device may determine thesize of the field based on a SCS of the scheduled cell and/or SCS of thescheduling cell (e.g., the CORESET associated with the DCI reception).In an example, the wireless device may determine the size of the fieldbased on one or more rules and/or one or more RRC parameters. Forexample, the field may indicate a first value indicating a PDSCH groupindex for a first portion/subset of the multiple PDSCHs. For example,the field may indicate a second value indicating a PDSCH group index fora second portion/subset of the multiple PDSCHs. For example, the firstportion/subset and/or the second portion/subset may bepre-defined/pre-configured.

FIG. 22 shows an example of grouping PDSCHs scheduled by a DCI,according to some embodiments. As shown in the figure, the DCI mayschedule four PDSCHs. The DCI may comprise a field indicating PDSCHgroup index(es) for the multiple PDSCHs (e.g., g1 for PDSCH-1, g2 forPDSCH-2, g3 for PDSCH-3, g4 for PDSCH-4]). For example, the field may bea bitmap (e.g., [1,0,1,1]) indicating a PDSCH group index independentlyfor each of the multiple PDSCHs. For example, the field may indicate twovalues (e.g., [1,0]), wherein each value indicates a PDSCH group indexfor a subset/portion of the multiple PDSCHs. For example, the field mayindicate a first PDSCH group index for a first portion/subset of thePDSCHs (e.g., [1] for g1 and g2). For example, the field may indicate asecond PDSCH group index for a second portion/subset of the PDSCHs(e.g., [0] for g3 and g4). For example, the first portion/subset may bea first half of the multiple PDSCHs (e.g., PDSCH-1 and PDSCH-2). Forexample, the second portion/subset may be a second half of the multiplePDSCHs (e.g., PDSCH-3 and PDSCH-4). For example, the firstportion/subset may comprise one or more first PDSCHs of the multiplePDSCHs in a first DL burst, e.g., contiguous PDSCHs before a non-zerogap (e.g., PDSCH-1 and PDSCH-2). For example, the second portion/subsetmay comprise one or more second PDSCHs of the multiple PDSCHs in asecond DL burst, e.g., contiguous PDSCHs after a non-zero gap (e.g.,PDSCH-3 and PDSCH-4).

The DCI scheduling multiple PDSCHs may comprise a HARQ feedback timingindicator indicating a slot for HARQ feedback transmission of themultiple PDSCHs. The DCI may comprise a PUCCH resource indicatorindicating a PUCCH resource for the HARQ feedback transmission. The DCIscheduling multiple PDSCHs may comprise a first field indicatingrequested PDSCH group(s). The requested PDSCH group(s) may indicate thatHARQ feedback of which PDSCH group(s) are requested to betransmitted/reported in the indicated PUCCH transmission. As shown inFIG. 22, the wireless device may determine a PUCCH transmission based onthe PRI and/or the HARQ feedback timing indicator.

The wireless device may determine to transmit/report HARQ feedbackinformation of PDSCH(s) of a first PDSCH group and/or PDSCH(s) of asecond PDSCH group, based on the first field, via the PUCCHtransmission. For example, the DCI/first field may indicate that HARQfeedback of PDSCHs associated with both/all PDSCH groups is requestedvia the indicated PUCCH transmission occasion. For example, theDCI/first field may indicate that HARQ feedback of PDSCHs associatedwith at least one PDSCH group is requested via the indicated PUCCHtransmission occasion. For example, the DCI/first field may indicatethat HARQ feedback of one or more PDSCHs associated with a first PDSCHgroup is requested via the indicated PUCCH transmission occasion. Forexample, the first PDSCH group may be the PDSCH group that comprises thefirst PDSCH (e.g., g1 of PDSCH-1 in FIG. 22). For example, the DCI/firstfield may indicate that HARQ feedback of one or more PDSCHs associatedwith a second PDSCH group (e.g., g2 of PDSCH-2 and/or g4 of last PDSCH)is requested via the indicated PUCCH transmission occasion.

The DCI scheduling multiple PDSCHs may comprise a first field indicatingrequested PDSCH group(s). In an example, the wireless device maydetermine a size and/or format of the first field based on one or moreparameters indicated configured by RRC signaling. For example, the RRCmessage(s) may comprise a first parameter and/or indicate a first valuefor the first parameter.

For example, the first parameter may indicate that a DCI schedulingmultiple PDSCHs may indicate that the multiple PDSCHs are of a same(first or second) PDSCH group. For example, the first parameter mayindicate that the DCI, scheduling multiple PDSCHs, may request HARQfeedback of scheduled PDSCH group (associated with the multiple PDSCHs)or both/all PDSCH groups. For example, the multi-PDSCH scheduling DCImay (only) schedule PDSCHs of a same PDSCH group. For example, theDCI/first field may indicate whether HARQ feedback of the scheduledPDSCH group is requested or HARQ feedback of both PDSCH groups arerequested (e.g., as in FIG. 21B). For example, the wireless device maydetermine the DCI field size/format based on FIG. 21B. For example, inFIG. 22, the DCI may indicate that the four PDSCHs are of same group(e.g., g1=g2=g3=g4=1). The first field (requested PDSCH group(s)) in theDCI may indicate a first value (e.g., 0), indicating that HARQ feedbackof PDSCH(s) associated with the scheduled PDSCH group (g=1) arerequested via the indicated PUCCH transmission occasion. The first fieldmay indicate a second value (e.g., 1), indicating that HARQ feedback ofPDSCH(s) associated with the scheduled PDSCH group (g=1) andnon-scheduled PDSCH group (g=0) are requested via the indicated PUCCHtransmission occasion. In this example, a DCI format may be simple, andthe DCI size/overhead may be reduced, however, the base station may onlyschedule PDSCHs of a same PDSCH group using a DCI.

For example, the first parameter may indicate that a DCI schedulingmultiple PDSCHs may indicate that the multiple PDSCHs may be ofdifferent (first and/or second) PDSCH groups. For example, the firstparameter may indicate that the DCI, scheduling multiple PDSCHs, mayrequest HARQ feedback of a first scheduled PDSCH group (associated witha first PDSCH of the multiple PDSCHs) or a second scheduled PDSCH group(associated with a second PDSCH of the multiple PDSCHs) or both/allPDSCH groups. For example, the multi-PDSCH scheduling DCI may schedulePDSCHs of different PDSCH groups. For example, the DCI may request HARQfeedback of any/either of the scheduled groups and/or both/all scheduledgroups.

A first HARQ codebook (e.g., enhanced dynamic codebook) comprising HARQfeedback of two or more PDSCH groups may be configured. In an example,the DCI may schedule multiple PDSCHs of two or more PDSCH groups. Forexample, one or more first PDSCHs of the multiple PDSCHs may be of afirst PDSCH group. For example, one or more second PDSCHs of themultiple PDSCHs may be of a second PDSCH group. The DCI may indicate aPUCCH transmission occasion for HARQ feedback transmission of at leastone of the first PDSCH group and the second PDSCH group. The DCI may ormay not comprise a field indicating a request of HARQ feedback of the atleast one of the first PDSCH group and the second PDSCH group. In anexample, a DCI scheduling multiple PDSCHs may (always) request HARQfeedback of both/all PDSCH groups via the indicated PUCCH transmissionoccasion. In an example, the DCI may request HARQ feedback of both/all(scheduled) PDSCH groups via the indicated PUCCH transmission occasion,in response to the RRC parameter(s) indicating that the DCI may schedulePDSCHs of different PDSCH groups. For example, in response to the RRCparameter(s) indicating that the DCI may schedule PDSCHs of differentPDSCH groups, the DCI may not comprise a “requested PDSCH group” field(e.g., the size of the field may be 0 bits). In an example, the(maximum) number of multiple PDSCHs may be equal to or greater than afirst value. In an example, a ratio of a first SCS of the scheduled celland a second SCS of the scheduling cell may be equal to or greater thanor smaller than a first value. For example, the UE may determine thesize/format of the DCI field indicating requested PDSCH group(s) basedon the first SCS and/or the second SCS. In an example, the DCI mayrequest HARQ feedback of a first and/or a second PDSCH group via theindicated PUCCH transmission occasion, e.g., in response to the RRCparameter(s) indicating that the DCI may schedule PDSCHs of differentPDSCH groups.

FIG. 23A and FIG. 23B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments. As shown in FIG. 23A, the UE may receive an RRCmessage indicating that a first parameter is not configured and/or isconfigured with a first value. The RRC message may indicate that a firstHARQ codebook (e.g., enhanced dynamic codebook) comprising HARQ feedbackof two or more PDSCH groups is configured. The first parameter mayindicate that a DCI may schedule multiple PDSCHs wherein the multiplePDSCHs are associated with a first/same PDSCH group. For example, the UEmay receive a DCI scheduling four PDSCHs as in FIG. 23A. The DCI mayindicate a PDSCH group index g for the four PDSCHs. The DCI may indicatea PUCCH transmission occasion for HARQ feedback of the multiple PDSCHs.The DCI may comprise a field indicating requested PDSCH group indexes.For example, as shown in FIG. 23B, the field may indicate a first value(e.g., 0) to request HARQ feedback of PDSCHs of the scheduled PDSCHgroup (e.g., g). The field may indicate a second value (e.g., 1) torequest HARQ feedback of PDSCHs of the scheduled PDSCH group andnon-scheduled PDSCH group (e.g., all/both PDSCH groups, 0 and 1). The UEmay transmit HARQ feedback of the multiple PDSCHs via the PUCCHtransmission indicated by the DCI. The PUCCH transmission may compriseHARQ feedback of one or more second PDSCHs, associated with therequested PDSCH group index(es). The one or more second PDSCHs may bescheduled by a second DCI, e.g., on a same or different cell.

FIG. 24A and FIG. 24B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments. As shown in FIG. 24A, the UE may receive an RRCmessage indicating that a first parameter is configured and/or isconfigured with a second value. The RRC message may indicate that afirst HARQ codebook (e.g., enhanced dynamic codebook) comprising HARQfeedback of two or more PDSCH groups is configured. The first parametermay indicate that a DCI may schedule multiple PDSCHs wherein themultiple PDSCHs are associated with different (e.g., first or second)PDSCH groups. For example, the UE may receive a DCI scheduling fourPDSCHs as in FIG. 24A. The DCI may indicate a PDSCH group index for eachof the four PDSCHs (e.g., g1 for PDSCH-1, g2 for PDSCH-2, g3 for PDSCH-3and g4 for PDSCH-4). The DCI may indicate a PUCCH transmission occasionfor HARQ feedback of at least one of the multiple PDSCHs. The DCI maycomprise a field indicating requested PDSCH group index(es). Thewireless device may determine the requested PDSCH group(s) based on thefield in the DCI and a first PDSCH of the multiple PDSCHs. For example,the UE may determine the requested PDSCH group(s) based on a first PDSCHgroup index associated with the first PDSCH. The first PDSCH may be anearliest PDSCH of the multiple PDSCHs (e.g., starts earlier than all).The first PDSCH may be a PDSCH of the multiple PDSCHs that is associatedwith a higher priority (e.g., based on a priority indicator field in theDCI). The first PDSCH may be a last PDSCH of the multiple PDSCHs.

For example, as shown in FIG. 24B, the request field in the DCI mayindicate a first value (e.g., 0) to request HARQ feedback of PDSCHsassociated with the PDSCH group index of the first scheduled PDSCH(e.g., g1). In an example, the request field may indicate the firstvalue (e.g., 0) to request HARQ feedback of PDSCHs associated with thePDSCH group index of the last scheduled PDSCH (e.g., g4). The field mayindicate a second value (e.g., 1) to request HARQ feedback of PDSCHs ofall the scheduled PDSCH groups (e.g., all/both PDSCH groups, 0 and 1).The UE may transmit HARQ feedback of one or more PDSCHs of the multiplePDSCHs via the PUCCH transmission indicated by the DCI. The one or morePDSCHs may be associated with the requested PDSCH group index(es). ThePUCCH transmission may comprise HARQ feedback of one or more secondPDSCHs, associated with the requested PDSCH group index(es). The one ormore second PDSCHs may be scheduled by a second DCI, e.g., on a same ordifferent cell.

In an example, the DCI scheduling multiple PDSCHs may comprise a fieldindicating PDSCH group request, wherein the size of the field may be 1bits. In an example, a first value of the first field in the DCIscheduling multiple PDSCHs may indicate requesting HARQ feedback of afirst/fixed PDSCH group index (e.g., group 0). In an example, a secondvalue of the first field in the DCI scheduling multiple PDSCHs mayindicate requesting HARQ feedback of a second/fixed PDSCH group index(e.g., group 1). In an example, the DCI may not comprise the field(e.g., the size of the field may be 0 bits). For example, the UE maydetermine the size of the field based on one or more RRC parameters. Theone or more RRC parameters may indicate whether the DCIscheduled/requests multiple PDSCHs associated with same or differentPDSCH groups. For example, in response to the size of the DCI fieldbeing 0 and/or the DCI not comprising the field, the UE may determinethat the DCI requests HARQ feedback of both (first and second) PDSCHgroups.

FIG. 25A and FIG. 25B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments. As shown in FIG. 25A, The wireless device may receivean RRC message indicating that a first HARQ codebook (e.g., enhanceddynamic codebook) is configured. The first HARQ codebook may compriseHARQ feedback of two or more PDSCH groups. The RRC message may indicatethat a DCI may schedule multiple PDSCHs associated with different (e.g.,two or more) PDSCH groups. The RRC message may indicate that a DCI mayrequest HARQ feedback of PDSCHs associated with different any/either ofthe PDSCH groups scheduled by the DCI. The wireless device may receive aDCI scheduling multiple PDSCHs. The DCI may indicate a PDSCH group indexfor one each of the multiple PDSCHs (e.g., g1, g2, g3, g4). In anexample, the DCI may schedule multiple PDSCHs of two or more PDSCHgroups. For example, one or more first PDSCHs of the multiple PDSCHs maybe of a first PDSCH group. For example, one or more second PDSCHs of themultiple PDSCHs may be of a second PDSCH group. The DCI may indicate aPUCCH transmission occasion for HARQ feedback transmission of at leastone of the first PDSCH group and the second PDSCH group.

The DCI scheduling multiple PDSCHs, e.g., of different/two or more PDSCHgroups, may comprise a field indicating HARQ feedback request of one ormore PDSCH groups via the indicated PUCCH transmission. FIG. 25B showsan example of the “request PDSCH group(s)” field in the DCI. Forexample, the field may comprise two bits, each bit associated with aPDSCH group index. For example, a first bit (e.g., MSB) of the field mayindicate whether a first PDSCH group associated with a first PDSCH groupindex (e.g., group 0) is requested or not. For example, a first value ofa bit (e.g., 0) may indicate that the HARQ feedback of the respectivePDSCH group is not requested. For example, a second value of a bit(e.g., 1) may indicate that the HARQ feedback of the respective PDSCHgroup is requested. For example, a second bit (e.g., LSB) of the fieldmay indicate whether a second PDSCH group associated with a second PDSCHgroup index (e.g., group 1) is requested or not. FIG. 25B shows a tableof such value requesting/triggering HARQ feedback of PDSCH group 0and/or PDSCH group 1.

In another example, a different table may be defined/configuredindicating a different mapping of the field values and the requestedPDSCH group(s). For example, the bits may be coded jointly (e.g., nodirect mapping between bits of the field and PDSCH groups). For example,a first value of the field (e.g., 00) may indicate a first PDSCH groupis requested. For example, a second value of the field (e.g., 01) mayindicate a second PDSCH group is requested. For example, a third valueof the field (e.g., 10) may indicate that the first and the second PDSCHgroups are requested. The wireless device may determine a size of thefield (e.g., two bits) based on a pre-defined/pre-configured parameter.The parameter may indicate a number of PDSCH groups associated with thefirst HARQ-ACK codebook. This embodiment may increase a field size, butmay enable the network to schedule PDSCH and/or PUCCH transmission moreflexibly and request HARQ feedback of each PDSCH group separately, withreduced restriction on the scheduling.

FIG. 26A and FIG. 26B show an example of requesting HARQ feedback of oneor more PDSCH groups by a DCI scheduling multiple PDSCHs, according tosome embodiments. As shown in FIG. 26A, the UE may receive an RRCmessage indicating that a first parameter is configured and/or isconfigured with a second value. The RRC message may indicate that afirst HARQ codebook (e.g., enhanced dynamic codebook) comprising HARQfeedback of two or more PDSCH groups is configured. The first parametermay indicate that a DCI may schedule multiple PDSCHs wherein themultiple PDSCHs are associated with different (e.g., first or second)PDSCH groups. For example, the UE may receive a DCI scheduling fourPDSCHs as in FIG. 26A. The DCI may indicate a PDSCH group index for eachof the four PDSCHs. For example, the DCI may indicate that PDSCH-1 andPDSCH-2 are associated with a first PDSCH group (e.g., group 1). Forexample, the DCI may indicate that PDSCH-3 and PDSCH-4 are associatedwith a second PDSCH group (e.g., group 0). The DCI may indicate a PUCCHtransmission occasion for HARQ feedback of at least one of the multiplePDSCHs. The DCI may comprise a field indicating requested PDSCH groupindex(es). The wireless device may determine the requested PDSCHgroup(s) based on the field in the DCI and a first PDSCH of the multiplePDSCHs. For example, the UE may determine the requested PDSCH group(s)based on a first PDSCH group index associated with the first PDSCH.

For example, as shown in FIG. 26B, the request field in the DCI mayindicate a first value (e.g., 0) to request HARQ feedback of PDSCHsassociated with the PDSCH group index of the first scheduled PDSCH(e.g., group 1). The UE may determine a slot for PUCCH transmissioncomprising HARQ feedback of the scheduled PDSCHs based on the HARQfeedback timing indicator indicated by the DCI (k1). The UE maydetermine the slot based on a second PDSCH that is associated with therequested PDSCH group index. For example, as shown in FIG. 26A, PDSCH-1and PDSCH-2 may be associated with the requested PDSCH group index(group 1). In this example, the UE may determine the slot for HARQtransmission based on a last scheduled PDSCH associated with therequested PDSCH group index, e.g., PDSCH-2. As shown in FIG. 26A, the UEmay apply the slot offset indicated by the HARQ feedback timingindicator value to the slot of PDSCH-2. The UE may transmit HARQfeedback of one or more PDSCHs of the multiple PDSCHs via the PUCCHtransmission indicated by the DCI. The one or more PDSCHs may beassociated with the requested PDSCH group index (group 1).

In an example, the wireless device may determine to postpone second HARQfeedback information corresponding to one or more second PDSCHs of themultiple PDSCHs, scheduled by a DCI. For example, the one or more secondPDSCHs may be associated with a second PDSCH group index (e.g., 0). Forexample, the one or more second PDSCHs may not be associated with (anyof) the requested PDSCH group index(es), indicated by the DCI. Forexample, in FIG. 26A and FIG. 26B, the UE may determine that PDSCH-3 andPDSCH-4 are associated with PDSCH group index 0, which is not requestedvia the indicated PUCCH transmission. For example, the UE may determinethat PDSCH-3 and PDSCH-4 are not associated with the requested PDSCHgroup (group 1). The UE may determine to postpone the HARQ feedback ofPDSCH-3 and PDSCH-4 based on the field in the DCI that indicates therequested PDSCH group(s), e.g., based on the field indicating the PDSCHgroup associated with the one or more second PDSCHs is not requested tobe transmitted via the indicated PUCCH transmission occasion in theindicated slot. In an example, the UE may determine that one or moresecond PDSCHs are associated with a non-numerical/inapplicable HARQfeedback timing indicator value (e.g., k1=−1 or NNK1). For example, thewireless device may receive a second DCI, e.g., after the multi-PDSCHscheduling DCI. The second DCI may indicate a slot comprising a secondPUCCH transmission occasion. The second DCI may indicate that the secondPUCCH transmission is associated with the second PDSCH group index. Forexample, the second DCI may request HARQ feedback of PDSCHs associatedwith the second PDSCH group index (e.g., group 0). The UE may transmitthe second HARQ feedback, of the one or more second PDSCHs of themultiple PDSCHs scheduled by a DCI, via the second PUCCH transmission ina second slot indicated by the second DCI.

In an example, a DCI scheduling multiple PDSCHs may indicate two (ormore) slots for HARQ feedback transmission. For example, the DCI maycomprise/indicate two (or more) HARQ feedback timing indicators (e.g.,k1-1 and k1-2). The wireless device may determine two (or more) PUCCHtransmission occasions, based on the DCI, for HARQ feedback transmissionof the multiple PDSCHs. In an example, a first PUCCH transmissionoccasion indicted by the DCI may be for HARQ feedback informationassociated with a first PDSCH group. In an example, a second PUCCHtransmission occasion indicted by the DCI may be for HARQ feedbackinformation associated with a second PDSCH group. For example, themapping of the PUCCHs and the PDSCH groups may be in the increasingorder of time/slot/starting symbol for PUCCHs and increasing order ofPDSCH group indexes. For example, the wireless device may determine thatan earlier PUCCH is for HARQ feedback information of PDSCH group index0, and/or that a later PUCCH is for HARQ feedback information of PDSCHgroup index 1.

In an example, RRC message(s) may comprise one or more parametersindicating that the DCI scheduling multiple PDSCHs may indicate/triggertwo (or more) PUCCH transmissions (e.g., in two or more slots). The UEmay determine that the first PUCCH comprises HARQ feedback of the firstPDSCH group and that the second PUCCH comprises HARQ feedback of thesecond PDSCH group, e.g., in response to: the first HARQ codebook (e.g.,enhanced dynamic codebook) being configured, and/or the one or moreparameters indicating that the DCI scheduling multiple PDSCHs maytrigger two (or more) PUCCH transmissions, and/or the RRC/DCI indicatingthat the multiple PDSCHs scheduled by the DCI are associated withdifferent/two or more PDSCH groups. In an example, the DCI may notcomprise a field indicating “requested PDSCH group(s)”, e.g., inresponse to the above. For example, the size of the field may be 0 bits.

In an example, the DCI may comprise a field indicating that a firstPUCCH (e.g., earlier PUCCH) is for HARQ feedback transmission of a firstPDSCH group associated with an indicated PDSCH group index. For example,the field may indicate value 0, indicating PDSCH group index 0 isassociated with the first PUCCH. For example, the field may indicatevalue 1, indicating PDSCH group index 1 is associated with the firstPUCCH. The wireless device may determine that theopposite/alternative/other PDSCH group is associated with the secondPUCCH. For example, the field may indicate value 0, indicating PDSCHgroup index 1 is associated with the second PUCCH. For example, thefield may indicate value 1, indicating PDSCH group index 0 is associatedwith the second PUCCH.

In an example, each of the two (or more) PUCCH transmissions maycomprise HARQ feedback information of one or more PDSCH groups. Forexample, the DCI may comprise a field, indicating requested PDSCHgroup(s) for each of the PUCCH transmissions. For example, the DCI maycomprise a first field indicating that a first PUCCH is for HARQfeedback transmission of a first and/or second PDSCH group. For example,the DCI may comprise a second field indicating that a second PUCCH isfor HARQ feedback transmission of a first and/or second PDSCH group.This embodiment may enable the network to request timely HARQ feedbackinformation for each of the PDSCH groups flexibly via either or both ofthe PUCCH transmissions.

FIG. 27 shows an example of requesting HARQ feedback of PDSCH groups bya DCI scheduling multiple PDSCHs and two respective PUCCHs, according tosome embodiments. The UE may receive an RRC message indicating that afirst HARQ codebook (e.g., enhanced dynamic codebook) comprising HARQfeedback of two or more PDSCH groups is configured. The RRC message mayindicate that a first parameter is configured and/or is configured witha first value. The first parameter may indicate that a DCI may schedulemultiple PDSCHs wherein the multiple PDSCHs are associated withdifferent (e.g., first or second) PDSCH groups. For example, the UE mayreceive a DCI scheduling four PDSCHs as in FIG. 27. The DCI may indicatea PDSCH group index for each of the four PDSCHs. For example, the DCImay indicate that PDSCH-1 and PDSCH-2 are associated with a first PDSCHgroup (e.g., group 0). For example, the DCI may indicate that PDSCH-3and PDSCH-4 are associated with a second PDSCH group (e.g., group 1).The DCI may indicate two PUCCH transmission occasions for HARQ feedbackof the multiple PDSCHs.

The wireless device may determine that a first PUCCH isrequesting/associated with a first PDSCH group, and/or that a secondPUCCH is requesting/associated with a second PDSCH group. In an example,the association of PUCCHs and PDSCH groups may be pre-defined, e.g.,first PUCCH for group 0 and second PUCCH for group 1. In an example, theassociation of PUCCHs and PDSCH groups may be based on PDSCH groupindexes of the scheduled PDSCHs, e.g., first PUCCH for PDSCH group indexassociated with a first PDSCH (e.g., g1 of PDSCH-1) and second PUCCH forPDSCH group index associated with a second/last PDSCH (e.g., g3 ofPDSCH-3 or g-4 of PDSCH-4). In an example, the DCI may comprise a fieldindicating a first requested PDSCH group index for the first PUCCH(e.g., DCI may indicate group 0). The wireless device may determine asecond requested PDSCH group index for the second PUCCH (e.g., group 1).For example, the second requested PDSCH group may be the complementaryof the first PDSCH group. For example, the UE may not expect that theDCI requests both PDSCH groups for the first PUCCH and/or the secondPUCCH.

The DCI may comprise a field indicating requested PDSCH group index(es)for each PUCCH transmission. The wireless device may determine the firstrequested PDSCH group(s) for a first PUCCH based on the field in the DCIand/or a first PDSCH of the multiple PDSCHs. For example, the UE maydetermine that a first PDSCH group (e.g., g1=0) is requested for PUCCH-1based on: a group index associated with the first PDSCH (PDSCH-1) and/orthe field indicating a first value (e.g., 0). For example, the UE maydetermine that both/all PDSCH groups (e.g., 0 and 1) are requested forPUCCH-1 based on: the field indicating a second value (e.g., 1). Thesame field may apply to the second PUCCH. For example, the wirelessdevice may determine the second requested PDSCH group(s) for the secondPUCCH based on the field in the DCI and/or a second PDSCH of themultiple PDSCHs. For example, the UE may determine that a second PDSCHgroup (e.g., g3/g4=1) is requested for PUCCH-2 based on: a group indexassociated with the second/last PDSCH (PDSCH-3 or 4) and/or the fieldindicating a first value (e.g., 0). For example, the UE may determinethat both/all PDSCH groups (e.g., 0 and 1) are requested for PUCCH-2based on: the field indicating a second value (e.g., 1). In anotherexample, the UE may determine the second requested PDSCH group(s) basedon a reverse value of the value indicated by the field.

In an example, the DCI, scheduling multiple PDSCHs associated withdifferent PDSCH groups, may comprise at least one field for requestingHARQ feedback of the multiple PDSCHs via two (or more) PUCCHs. The DCImay indicate two (or more) slots for the two (or more) PUCCHs. Forexample, the at least one field may indicate a first value, indicatingHARQ feedback information of which PDSCH group(s) is requested for afirst PUCCH indicated by the DCI. For example, the at least one fieldmay indicate a second value, indicating HARQ feedback information ofwhich PDSCH group(s) is requested for a second PUCCH indicated by theDCI. The two requested PDSCH group(s) associated with each PUCCH may beindependent or the same.

In an example, the wireless device may determine a (larger) size of therequest field (e.g., 2 bits), e.g., in response to the DCI triggeringmore than one PUCCH transmissions. For example, a first value of thefield (e.g., 00) may indicate requesting a first PDSCH group index for afirst PUCCH and a second PDSCH group index for a second PUCCH. Forexample, a second value of the field (e.g., 01) may indicate requestinga first PDSCH group index for the first PUCCH and both first and secondPDSCH group indexes for the second PUCCH. For example, a third value ofthe field (e.g., 10) may indicate requesting both first and second PDSCHgroup indexes for the first PUCCH and the second PDSCH group index forthe second PUCCH. For example, a fourth value of the field (e.g., 11)may indicate requesting both first and second PDSCH group indexes forthe first PUCCH and both first and second PDSCH group indexes for thesecond PUCCH. For example, first PDSCH group index may be 0 or 1. Forexample, first PDSCH group index may be the PDSCH group index associatedwith a first PDSCH of the multiple PDSCHs scheduled by the DCI.

In an example, the DCI scheduling multiple PDSCH, may indicate that oneor more first PDSCHs of the multiple PDSCHs are of a first PDSCH group,and one or more second PDSCHs of the multiple PDSCHs are of a secondPDSCH group. The DCI may comprise a field indicating/requesting HARQfeedback of the first PDSCH group via an indicated PUCCH transmission.The wireless device may transmit HARQ feedback of the one or more firstPDSCHs via the PUCCH. The wireless device may transmit HARQ feedback ofone or more third PDSCHs, e.g., scheduled by at least a second DCI, viathe PUCCH, wherein the one or more third PDSCHs are associated with thefirst PDSCH group index. The wireless device may transmit second HARQfeedback of the one or more second PDSCHs via the PUCCH, wherein the oneor more second PDSCHs are associated with the second PPSCH group indexand/or the DCI does not indicate a request of HARQ feedback of thesecond PDSCH group via the PUCCH. The wireless device may not transmitfourth HARQ feedback of one or more fourth PDSCH, e.g., scheduled by atleast a third DCI, via the PUCCH, wherein the one or more fourth PDSCHsare associated with the second PDSCH group index. For example, thewireless device may append the second HARQ feedback to the HARQfeedback/sub-codebook of the one or more first PDSCHs associated withthe requested (first) PDSCH group.

In an example, the UE may not be expected to be configured with thefirst HARQ codebook (e.g., enhanced dynamic codebook), when multi-PDSCHscheduling is configured/enabled. In an example, a DCI schedulingmultiple PDSCHs may trigger a one-shot HARQ feedback. In an example, aDCI scheduling multiple PDSCHs may trigger a one-shot HARQ feedback, ifthe first codebook is not configured/enabled. In an example, a DCIscheduling multiple PDSCHs may trigger a one-shot HARQ feedback if anumber of multiple PDSCHs is above a value.

What is claimed is:
 1. A method comprising: receiving, by a wirelessdevice, a downlink control information (DCI) indicating: physicaldownlink shared channels (PDSCHs) across slots in a cell; group indexesof the PDSCHs, respectively, wherein each of the group indexes comprisesone of a first value or a second value; and an uplink control channelfor transmitting feedback information of one or more PDSCHs with one ormore respective group indexes comprising a same value as a first groupindex of a first PDSCH of the PDSCHs; determining that the first groupindex of the first PDSCH comprises the first value; and transmitting,via the uplink control channel, feedback information of one or morefirst PDSCHs, from the PDSCHs, with one or more respective first groupindexes comprising the first value.
 2. The method of claim 1, whereinthe DCI comprises a field indicating a number of groups of PDSCHs forwhich transmission of feedback information is requested via the uplinkcontrol channel.
 3. The method of claim 2, further comprisingdetermining, based on the field indicating the number of groups to be afirst predefined value, that the uplink control channel is fortransmitting feedback information of one or more PDSCHs with one or morerespective group indexes comprising the same value as the first groupindex of the first PDSCH.
 4. The method of claim 1, wherein the DCIcomprises a PDSCH group index field with a value indicating the groupindexes of the PDSCHs, respectively.
 5. The method of claim 1, furthercomprising receiving a radio resource control (RRC) message comprising aparameter indicating that multiple PDSCHs scheduled by one DCI areassociated with group indexes comprising more than one value.
 6. Themethod of claim 1, wherein the first PDSCH is an earliest PDSCH of thePDSCHs.
 7. The method of claim 1, wherein the first PDSCH is a latestPDSCH of the plurality of PDSCHs.
 8. The method of claim 1, wherein thefirst PDSCH is a PDSCH of the PDSCHs with a high priority.
 9. The methodof claim 1, further comprising transmitting, via a second uplink controlchannel, feedback information of one or more second PDSCHs, from thePDSCHs, with one or more respective second group indexes comprising thesecond value.
 10. The method of claim 9, wherein the DCI furtherindicates the second uplink control channel.
 11. A wireless devicecomprising: one or more processors; and memory storing instructionsthat, when executed by the one or more processors, cause the wirelessdevice to: receive a downlink control information (DCI) indicating:physical downlink shared channels (PDSCHs) across slots in a cell; groupindexes of the PDSCHs, respectively, wherein each of the group indexescomprises one of a first value or a second value; and an uplink controlchannel for transmitting feedback information of one or more PDSCHs withone or more respective group indexes comprising a same value as a firstgroup index of a first PDSCH of the PDSCHs; determine that the firstgroup index of the first PDSCH comprises the first value; and transmit,via the uplink control channel, feedback information of one or morefirst PDSCHs, from the PDSCHs, with one or more respective first groupindexes comprising the first value.
 12. The wireless device of claim 11,wherein the DCI comprises a field indicating a number of groups ofPDSCHs for which transmission of feedback information is requested viathe uplink control channel.
 13. The wireless device of claim 12, whereinthe instructions further cause the wireless device to determine, basedon the field indicating the number of groups to be a first predefinedvalue, that the uplink control channel is for transmitting feedbackinformation of one or more PDSCHs with one or more respective groupindexes comprising the same value as the first group index of the firstPDSCH.
 14. The wireless device of claim 11, wherein the DCI comprises aPDSCH group index field with a value indicating the group indexes of thePDSCHs, respectively.
 15. The wireless device of claim 11, wherein theinstructions further cause the wireless device to receive a radioresource control (RRC) message comprising a parameter indicating thatmultiple PDSCHs scheduled by one DCI are associated with group indexescomprising more than one value.
 16. The wireless device of claim 11,wherein the first PDSCH is an earliest PDSCH of the PDSCHs.
 17. Thewireless device of claim 11, wherein the first PDSCH is a latest PDSCHof the plurality of PDSCHs.
 18. The wireless device of claim 11, whereinthe first PDSCH is a PDSCH of the PDSCHs with a high priority.
 19. Thewireless device of claim 11, wherein the instructions further cause thewireless device to transmit, via a second uplink control channel,feedback information of one or more second PDSCHs, from the PDSCHs, withone or more respective second group indexes comprising the second value,and wherein the DCI further indicates the second uplink control channel.20. A system comprising: a base station comprising: one or more firstprocessors and first memory storing first instructions that, whenexecuted by the one or more first processors, cause the base station to:transmit a downlink control information (DCI) indicating: physicaldownlink shared channels (PDSCHs) across slots in a cell; group indexesof the PDSCHs, respectively, wherein each of the group indexes comprisesone of a first value or a second value; and an uplink control channelfor transmitting feedback information of one or more PDSCHs with one ormore respective group indexes comprising a same value as a first groupindex of a first PDSCH of the PDSCHs; and a wireless device comprising:one or more second processors and second memory storing secondinstructions that, when executed by the one or more second processors,cause the wireless device to: receive the DCI; determine that the firstgroup index of the first PDSCH comprises the first value; and transmit,via the uplink control channel, feedback information of one or morefirst PDSCHs, from the PDSCHs, with one or more respective first groupindexes comprising the first value.